U. S. DEPARTMENT OF AGRICULTURE, 

BUREAU OF ANIMAL INDUSTRY.— Bulletin No. 78. 

S F D. E. SALMON, D. V. M., Chief of Bureau. 

i^7 



TEXAS FEVER 



(OTHERWISE KNOWN AS TICK FEVER. SPLENETIC FEVER. 
OR SOUTHERN CATTLE FEVER), 



METHODS FOR ITS PREVENTION. 



BY 



JOHN R. MOHLER, V. M. D., 

Chief of Pathological Division, Bureau of Animal hidustry. 




WASHINGTON: 

GOVERNMENT PRINTING OFFICE. 

1905. 




Class 
Book_ 



r 



U. S. DEPARTMENT OF AGRICULTURE. 

BUREAU OF ANIMAL I NDUSTRY.— Bulletin No. 78. 

D. E. SALMON, D, V. M., Chief of Bureau. 



Yf y 



TEXAS FEVER 



(OTHERWISE KNOWN AS TICK FEVER, SPLENETIC FEVER, 
OR SOUTHERN CATTLE FEVER), 



METHODS FOR ITS PREVENTION. 



JOHN R. MOHLER, V; M. D., 

Chief of Pathological Division, Bureau of Animal Industry. 




WASHINGTON: 

GOVERNMENT PRINTING OFFICE 
1905. 



".fjv^jwjii 






LETTER OF TRANSMITTAL. 



U. S. Department of Ageiculture, 

Bureau of Animal Industry, 

Washington^ D. C.^ August 4, 1905. 
Sir: I have the honor to transmit herewith a manuscript entitled 
"Texas fever (otherwise known as tick fever, splenetic fever, or 
Southern cattle fever), with methods for its prevention," by John R. 
Mohler, V. M. D., chief of the Pathological Division of this Bureau. 
This article deals in a practical Avay with a disease Avhich causes 
great annual loss to the stockmen of this country. 

I recommend that this manuscript be published as Bulletin No. 78 
of the Bureau of Animal Industry series. 
Respectfully, 

D. E. Salmon, 
Chief of Bureau. 
Hon. James Wilson, 

Secretary of Agriculture. 



OCT 20 iyu6 

a Of a 



CONTENTS, 



Page. 

Introduction 5 

Name and synonyms . _ . 6 

Definition 6 

History and distribution 7 

Cause of the disease 9 

Life history of the cattle tick and the part played by it in producing Texas 

fever 10 

How to distinguish harmless ticks found on cattle from Texas fever ticks. . 12 
Some objections to the role of ticks as carriers of Texas fever, with expla- 
nations • 15 

Other injurious effects of cattle ticks 18 

Loss occasioned by cattle ticks 19 

Period of development of disease after exposure to ticks 22 

Symptoms 22 

Appearance after death 25 

Course and termination 26 

Infective character 27 

Animals affected . _ / 28 

Diseases mistaken for Texas fever 28 

Treatment 29 

Prevention: 

How to free cattle of ticks-— 

Picking or brushing ticks off cattle 30 

Smearing or spraying cattle with a disinfecting solution 30 

Dipping in a vat . . . _ 31 

By the ' ' soiling " ' method 32 

How to free pastures of ticks — 

By excluding cattle for a definite period .- . 33 

By cultivation 33 

By burning off the grass <. 33 

How to free cattle and pastures of ticks at the same time- 
By the * • feed-lot ' ' method . 35 

By pasture rotation ...... 36 

Immunization of susceptible cattle— 

By blood inoculation 39 

By infesting with ticks 42 

Federal sanitary regulations .... 42 

Other important measures for reducing the infected area 44 



LLUSTRATIONS 



PLATES. 

Page. 

Plate 1, fig. 1. Mature female cattle tick (X 4); fig. la. Mature female cattle 
tick (natural size); fig. lb. Head and shield of same (X 15): fig. 
2. Mature female castor-bean tick (X 4): fig. 2a. Mature female 
castor-bean tick (natural size); fig. 2b. Head and shield of 
same (X 15); fig. B. Mature female net tick (X 4); fig. 3a. Ma- 
ture female net tick (natural size) ; fig. 3b. Head and shield of 
same (X 15); fig. 4. Mature female dog, or wood, tick (X 4); 
fig. 4a. Mature female dog, or wood, tick (natural size) ; fig. 4b. 
Head and shield of same (X 15) 16 

2, fig. 1. Mature female Lone Star tick (X 4) : fig. la. Mature female 

Lone Star tick (natural size) ; fig. lb. Head and shield of same 
(X 15); fig. 2. Mature female ear tick (X 4); fig. 2a. Mature 
female ear tick (natural size) : fig. 2b. Head of same protruding 
from beneath (X 15); fig. 3. Mature female chicken tick (X 4); 
fig. 3a. Mature female chicken tick (natural size); fig. 3b. Up- 
per portion of same, head invisible (X 10) ; fig. 4. Mat re female 
European dog tick (X 4); fig. 4a. Mature female European dog 
tick (natural size); fig. 4b. Head and shield of same (X 15) 16 

3, fig. 1. Larva of cattle tick (X 25); fig. 2. Larva of cattle tick 

(natural size); fig. 3. Mature female and eggs (natural size); 
fig. 4. Hide, showing cattle ticks: fig. 5. Blood cells containing 
Texas fever protozoa; fig. 6. Male cattle tick (X 15); fig. 7. Male 
cattle tick (natural size) ; fig. 8. Young female cattle tick (X 15) ; 
fig. 9. Young female cattle tick (natural size) ; fig. 10. Various 
stages and colorations of cattle ticks 16 

FIGURES. 

Fig. 1. Boundary line of the district infected with Texas fever 7 

2. Cleaning cattle and soil by " ' feed-lot " ' method 34 

3. Cleaning cattle and soil by pasture rotation - 37 

4 



TEXAS FEVER 

(Otherwise kiiowii iis Tiek Fever, Spleiietie Fever, or Soiitlierii Cattle Fever), 
WITH METHODS FOR ITS PREVENTION. 

By John R. Mohler, V. M. T>., 
Chief of Pathological Division, Bureau of Animal Industry. 

INTRODUCTION. 

Texas fever, a very serious obstacle to the development and pros- 
perit}" of the cattle indiistrv of the South, has been pretty thoroughly 
understood since the investigations and discoveries made by Smith 
and Kilborne and published in 1893 as Bulletin ^o. 1 of the Bureau 
of Animal Industr}'. Their work showed conclusively that the 
cause of the disease was an intracorpuscular parasite (one living 
within the blood cells), the intermediate stage of the development of 
Avhich occurred in the cattle tick, thus making this tick the indirect 
but absolutely essential factor in the natural production of the dis- 
ease. Above the latitude where the cattle tick is destroyed b}^ the 
cold of winter the disease can be thoroughly controlled by keeping 
Southern tick-infested cattle from passing through the country dur- 
ing certain seasons. It is also well known that by completely sever- 
ing the relations of the fever tick and native cattle the former may 
be exterminated, thus making it possible by intelligent and energetic 
measures to eradicate the disease, and thereb}^ to remove a constant 
menace to the Southern cattle breeder, feeder, and dairyman. In 
spite of these facts, however, comparatively little work has been done 
along the line of controlling this disease in the infected districts 
either by State legislation, by county or parish regulations, or by the 
combined action of cattle breeders over a large extent of country. 
This probably has been due in a great measure to a lack of knowledge 
or indiiference on the part of legislators and farmers to the advan- 
tage which may accrue from their combined efforts. It is with the 
object of stimulating them and suggesting plans to eradicate the cat- 
tle tick, and thereby to enable stock owners of the South to escape 
the loss of millions of dollars annually sustained by them as a result 
of its devastations, that this bulletin is issued. Especial pains will 
be taken to make as clear as possible the absolutely proved facts re- 

5 



6 BUREAU OF ANTMAL INDUSTRY. 

yarding the disoaso, so that every cattle owner will l)e able to recog- 
nize the niahidy and the tick which causes it, and to carry out 
successfully measures for eliminating this tick as well as for immu- 
nizing cattle brought into the infected area. 

NAME AND SYNONYMS. 

Of the long list of terms applied to this disease, none seems to fill 
completely all the requirements of an ideal name. " Texas fever," 
although the term most commonly in use in this country, is a very 
misleading one, as it gives to the uninformed the impression that 
the disease is confined to the State of Texas. Southern cattle fever 
is especially inapplicable, as the disease is usually more virulent in 
Northern cattle when once infection becomes manifest than in 
Southern cattle. Probably the best name to apply to the disease, 
since it can only be transmitted in nature by the tick Boophilus an- 
nulatus^ is that of tick fever. This designation, hoAvever, is com- 
paratively little used, and, as the disease is generally recognized in 
this countr}^ under the name of Texas fever, this term will be used 
in the present work. Other synonyms besides those already men- 
tioned are red water, black water, distemper, acclimation fever, mur- 
rain, dry murrain, yellow murrain, bloody murrain, Mexican fever, 
Spanish fever, splenic (or splenetic) fever, protozoan cattle fever, 
hemaglobinuria, tristeza, paludism of cattle, bovine periodic fever, 
bovine piroplasmosis, and bovine malaria. 

DEFINITION. 

Texas fever is a specific infectious disease of the blood of cattle, 
caused by the development and activity of minute animal parasites 
(protozoa) which are conveyed to the affected animals by means of 
the cattle tick Boophilus annnlatus. After the microscopic pro- 
tozoan is injected into the blood of a susceptible animal it attacks the 
red blood cells, causing their disintegration. The disease is charac- 
terized by. high fever, by destruction of red corpuscles, and the con- 
sequent excretion of the coloring matter of the blood by the kidneys, 
causing a reddish discoloration of the urine, by enlarged spleen, 
engorged liver, thick, flaky bile, more or less jaundice, emaciation, 
and death in from 10 per cent of the chronic to 90 per cent of the 
acute cases. The peculiarity about this disease is that the animals 
responsible for the spread of the malady are apparently healthy, al- 
though containing the protozoa in their blood, while those that 
become diseased do not, as a rule, convey the affection to others. In 
the few instances where they do, it is not by contact, but indirectly 
by means of the progeny of the ticks from these diseased animals. 
Infection is not transmitted by the air, urine, saliva, manure, or by 
any other natural manner than by cattle ticks. 



TEXAS FEVER AND ITS PREVENTION. 7 

HISTORY AM) DISTRIBI TIOX. 

The ])la('o of ori<>iii of this disoaso is unknown, but it has certainly 
existed for centuries in some countries of Europe, anion"- which may 
be mentioned southern France, Italy, Turkey, and along the Danube 
River in Roumania. It is also prevalent in West Indies, Mexico, 
Central America, South America, Australia, Xorth Africa, East 
Africa, South Africa, Ireland. Finland, southern Rnssia, China, 
Japan, Java, Borneo, and the Philippine Islands. 

It was probably introduced into the Ignited States with the impor- 
tations of cattle by the Spaniards during the early colonization of 
Mexico and southern United States. 

The disease caused continual losses year after year during the early 
history of our country. In spite of this fact, it seems to have been 
described first by Dr. J. Pease toward the close of the eighteenth cen- 




Boundai-y line of the district infected with Texas fever. 



tury. At that time a very seA^ere outbreak of the disease occurred in 
Lancaster County, Pa., and Pease, after investigating the conditions, 
claimed it to have been due directly to the shipment of some Xorth 
Carolina cattle into the State. 

Experience soon showed that the invariable result following the 
transportation of Southern cattle into the Xorthern States was the 
death of all Xorthern cattle along the roads and on the pastures over 
which the Southern cattle had traveled, although the latter animals 
remained perfectly healthy. In the same way Xorthern cattle taken 
South were almost invariably attacked with the malad}^ 

In 1868 Texas cattle shipped north into the States of Illinois and 
Indiana early in the summer caused enormous losses, and cattle 



8 BUREAU OF ANIMAL INDUSTRY. 

shipped from these States to the Eastern markets died during trans- 
l)ortati()n. These great k)sses prompted the study of the disease by 
many scientific men, whose investigations soon established the great 
danger of allowing Southern cattle to pass into the Northern States 
during hot weather, and finally resulted in 1885 in the location of the 
infected district and the establishment of the Texas fever quarantine 
line in 1891 by Dr. D. E. Salmon, Avhich have been the most im- 
portant steps yet taken toward controlling the great losses from the 
disease. 

Smith was the first (1889) to recognize and describe as protozoa 
the intracorpuscular parasites which are the direct causative 
agents of the disease, although Babes had previously diagnosed them 
as bacteria (Hematococcus) for Starcovici, who found them in the 
blood of Roumanian cattle in 1888. In 1889 and 1890 Kilborne, by 
conclusive field experiments suggested by Salmon, proved the pres- 
ence of the cattle tick to be essential in the transmission of the dis- 
ease. It is of interest to note that this was the first experimental 
proof furnished on the subject of diseases borne by insects, or diseases 
that can be carried from one animal to another only by an inter- 
mediary host. This mode of transmitting infections has since be- 
come quite familiar to the public by the discovery that certain species 
of mosquitoes spread malaria and yellow fever to man. 

It was suggested by the experiments of the Bureau of Animal 
Industry in 1892 and 1893 that, through the production of a mild, 
nonfatal attack of Texas fever in Northern cattle, a very consider- 
able amount of protection is afforded against the disease when these 
cattle are subsequently exposed to the infection on tick-infested pas- 
tures. The methods advanced for producing such a mild, nonfatal 
attack were (1) the artificial inoculation, either into a vein or under 
the skin of susceptible animals during the fall or winter, of defibri- 
nated blood from an immune cow; or (2) the less certain way, con- 
sisting of the exposure of the nonimmune animal to ticks by confining 
the animal to an inclosed pasture after scattering ripe egg-laying 
ticks over the grass. 

From 1895 to 1897 additional experiments were conducted by the 
Bureau with the object of further demonstrating the possibility of 
immunizing cattle against Texas fever by the use of blood obtained 
from Southern cattle; and experiments wdth a similar object in 
view were likewise instigated and perfected about this time at the 
experiment stations of Missouri, Texas, Mississippi, and Louisiana, 
and by the Australian Government, wdth most excellent results. 
Later experiments with the disease have been performed principally 
with the view of obtaining a satisfactory chemical solution in which 
to dip tick-infested cattle for the purpose of destroying these para- 



TEXAS FEVER AND ITS PREVENTION. 9 

sites, and of developing some methods that may be easily carried out 
for freeing fields, farms, and counties of the cattle tick. 

CAUSE OF THE DISEASE. 

The primary or direct cause of Texas fever is the microparasite 
Piroplasma higeminuni^ belonging to the lowest form of animal life, 
the protozoa. This minute parasite is found in the blood (PL 3, 
fig. 5) in every case of Texas fever; and by inoculating blood con- 
taining it into susceptible cattle, the disease can be invariably trans- 
mitted, thus proving its direct causative effect in the production of 
the malady. After gaining the circulation the piroplasma under- 
goes several stages of development which can be studied by examining 
carefully prepared fresh preparations of the infected blood under the 
microscope for several successive days. In the first stage the parasite 
is inside the red blood cell near its margin and is nonmotile and pale, 
making it difficult to distinguish in the unstained preparations. This 
stage is principally seen in the chronic type of the disease in which 
from 5 to 50 per cent of the red blood cells are invaded. This single 
body later divides incompletely into two small roundish bodies 
which are partially connected by a narrow intervening strand, and 
this form may remain in the blood for several days at least. Some- 
times four, five, or even six parasites may be observed in one blood cell. 
In the next stage the minute double rounded bodies become enlarged 
and spindle-shaped. They probably remain attached, however, as 
in stained preparations a minute delicate filament may frequently 
be made out connecting them. The tAvo bodies enlarge uniformly and 
assume a pear-shaped appearance. It is this stage of the life cycle 
which is seen in the acute form of the disease, and from one-half of 
1 to 2 per cent of the red cells are usually invaded — rarely as many as 
10 per cent. The parasites at this time occupy nearly one-fourth 
of the body of the red blood cells and, as can be readily understood, 
exert a detrimental influence upon them. Their periphery becomes 
shriveled or crumpled, and the blood cells finally break up, liberating 
the piroplasma, which may be observed as free bodies in the circula- 
tion — most frequently in the kidneys. The stage of reproduction or 
multiplication of this protozoa has never been observed in this labora- 
tory, but that it does occur is proved by the fact that inoculation of 
a small quantity of virulent blood into susceptible animals will give 
rise to the disease Avith myriads of parasites in the blood. Hunt, 
of Queensland, states that reproduction occurs by the development of 
the protozoa into crescentic or spheroidal bodies Avhich burst and lib- 
erate the young forms Avhich they contain. The natural path of 
entrance of these protozoa, however, is by one channel only, namely, 
through the bite of the cattle tick. A knowledge of the habits and life 
10679— No. 78— 06 m 2 



10 BUKEAU OF ANIMAL INDUSTRY. 

history of the hitter is extremely important in controlling the disease, 
because without this tick Texas fever would be unknown. 

LIFE HISTOKY OF THE (BATTLE TICK AND THE PART PLAYED BY IT IN 
PRODUCING TEXAS FEVER. 

In stating the interesting and important life history of this tick, 
we will start at the point Avhere the fully developed and fertilized 
female, being engorged with blood and ready to lay her eggs, loosens 
her hold on the bovine animal and drops to the ground. Upon reach- 
ing the ground she may lie quietly for several days before depositing 
her eggs, which may consume from four to eight days in summer and 
two w^eeks or even longer in the fall. The number of eggs laid by a 
fully developed female varies from 1,500 to 3,000, while the immature 
females also lay eggs, but in much smaller numbers. After laying is 
finished the female is small and shriveled up and, having fulfilled her 
mission, soon dies (PI. 3, fig. 3). The eggs, which are light brown 
and waxy in appearance, proceed to develop the larvse, or seed 
ticks, the time required for which varies from thirteen days to six 
w^eeks, depending on the conditions of temperature, moisture, soil, 
etc. These eggs, however, are very tenacious of life, and under 
unfavorable conditions may remain dormant for several months — 
from late fall to early spring. • 

The larvse, or seed ticks, are minute six-legged parasites of a 
brownish waxy color, and about 3^2 of an inch in size (PL 3, fig. 2). 
They crawl quite actively about on the ground and among leaves, 
bunching in large numbers upon grass bJades, shrubs, weeds, and 
fence posts, to await an opportunity for attachment to their passing 
host. In case no cattle or horses are present, the parasitism is so per- 
fect that no further development occurs, and death finally results. 
It is know^n, however, that these larval forms can liA^e for three or 
four months on the ground in warm weather independent of their 
host, and from late September until April during an open w^inter. 
When they find cattle, how^ever, they crawl up the legs and attach 
themselves to the soft skin inside the thighs and flanks, on the es- 
cutcheon, along the belly and brisket, around the root of the tail, and 
inside the forelegs (PL 3, fig. 1). The}^ obtain their nourishment 
by drawing blood from the host, and can cause the fever at this stage, 
although so small as scarcely to be detected by the naked eye. After 
being on the animal about one week the seed tick casts its covering 
(molts) and appears as the eight-legged nymph stage of the parasite, 
having added one pair of legs posteriorly. During the nymphal 
stage the sexual organs develop, and at the second molting from the 
nymphal to the adult stage the sexual organs are complete. The 
male and female at this stage are about the same size, as the female 



TEXAS FEVER AND ITS PREVENTION. 11 

does not becoiiie very large until after she becomes fertilized, which 
occurs about two weeks after the six-legged seed tick reaches its host, 
or shortly after the second molting (PL 3, figs. 7 and 9). After in- 
tercourse with the male the female slowly enlarges for six to twenty 
days in summer, and then rapidly increases in size in the course of a 
day or two before dropping off the animal. In fall and Avinter de- 
velopment occurs more slowly, the tick not falling off for six weeks or 
more. After reaching the ground the female soon commences to de- 
posit eggs, thus completing the life cycle, which requires from 
six to ten weeks in Avarm Aveather, or a much longer period during the 
cold season. 

Although young ticks are very actiA^e, neither they nor the adult 
ticks are capable of craAvling very far, but they may be transported 
long distances by animals, by rains, by winds, cattle cars, hides, and 
on the clothing of man. Hence the constant danger that tick- free 
pastures beloAv the line may become infested Avith ticks at any time. 

The tick causes more or less irritation of the skin at the point Avhere 
it attaches, and it has been suggested that it injects some poisonous 
substance into its bites along Avith the Plroplasma Mgeminiim^ which 
reduces the Adtality of the tissues and enables the protozoan to multi- 
ply, and to get a start, so to speak. This is considered to be the case, 
because it has frequently been experimentally attempted to reproduce 
Texas fcA^er by inoculating susceptible animals both into the vein and 
under the skin with salt solution emulsions of ticks ground up in a 
mortar, and also by feeding ticks, but uniformly Avithout success. 
HoAveA^er, it is probable that the protozoan passes a resting stage of its 
life cycle in the body of the ticks, Avhich Avould explain these failures. 

The great length of time required for the appearance of the disease 
in Northern cuttle after the passage of tick-bearing cattle through the 
country (thirteeen to ninety days) can easily be accounted for by the 
life history of the tick. It is necessary before the disease appears for 
the fully developed fertilized female to drop off the Southern cattle 
and deposit the eggs, and for them to hatch into the six-legged larvae. 
These must then crawl up on the Northern cattle and insert the micro- 
parasites they carry through the bites made in the skin in procuring 
their nourishment. Texas fever folloAvs. It Avill thus be seen that 
these females transmit the infection through their eggs to their 
progeny, and the latter have the poAver to infect any susceptible 
animal to Avhicli they attach. The disease therefore is not conveyed 
by the same ticks Avhich take up the infected blood, but only through 
the generation descending from them. 

The first experiment performed by Kilborne in proving the ''tick 
theory '■ consisted in placing four North Carolina tick-infested cattle 
in a special inclosure, and at various times thereafter placing 13 sus- 



12 BUREAU OF ANIMAL INDUSTRY. 

ceptible animals in the same field; of these 10 died of the disease, 
2 recovered, and 1 was unaffected. In the second experiment all 
ticks were carefully picked by hand from 3 North Carolina cattle 
which were placed in a second noninfected field. Five susceptible 
cattle were then placed in the field with these tick-free North Caro- 
lina cattle and all remained perfectly healthy. Finally, in 1890. 
young ticks, hatched and raised in the laboratory, were placed on 4 
susceptible animals and produced Texas fever in every case, thereby 
proving that the tick was responsible for the disease. Other experi- 
ments have been performed by feeding virulent materials, by expos- 
ing cattle to the urine, manure, and nasal secretion of sick animals, 
and to the blood and viscera of cattle dead of Texas fever, but always 
Avith negative results, thus eliminating these as the causative factors, 
and furnishing indirect evidence substantiating the " tick theory." 

HOW TO DISTINGUISH HARMLESS TICKS FOUND ON CATTLE FROM TEXAS - 

FEVER TICKS. 

The Texas- fever tick, also called the cattle or cow tick, is continu- 
ally confused Avith a number of other ticks occasionally found on 
cattle, but, so far as concerns the transmission of Texas fever, en- 
tirely harmless to them. It is this lack of identification and the 
inability of many cattle owners to distinguish between these A^arious 
ticks that haA^e caused so many diverse opinions regarding the impor- 
tant part played by the Texas-feA^er tick in transmitting Texas feA^er. 
In order to differentiate betAveen the ticks that may be found on 
cattle, a brief description of the upper surface of the maturing or 
adult female of each is here given, together w^ith illustrations of 
this vicAv of the ticks, natural size, and also magnified four diameters. 
It Avas not thought necessary to furnish the stockman AAdth a descrip- 
tion of the male and immature female ticks at this time, inasmuch 
as these ticks are much smaller in size, and therefore it is more diffi- 
cult to recognize the vg^rious differences betAveen these forms of the 
different species by means of the naked eye. Moreover, it is usually 
possible to secure a maturing female in those instances Avhere a diag- 
nosis is desired, and at this stage of development ticks possess certain 
characteristic features or markings Avhich should cause them to 
be classified readily as harmful or harmless even by superficial 
examination. Ticks said to be Texas-fever ticks have been reported 
by some stockmen as infesting susceptible cattle Avithout producing 
Texas fever, and by others mature ticks, presumed to be Texas- 
fever ticks, have been found on uncultivated land and in Avoods 
Avhere cattle have never grazed. These statements have been fre- 
quently adA^anced in order to refute the experiments already men- 
tioned as to the essential part played by the Texas-fever tick in caus- 



TEXAS FEVER AND ITS PREVENTION. 18 

inof Texas fever. If fever ticks have been found on nonimmune 
cattle without producing Texas fever, the exphniation is that these 
particuhir ticks were probably noninfectious, which in rare cases 
is seen, as described in section on " Some objections to the role of 
ticks as carriers of Texas fever, with explanations.'' On the other 
hand, it has very frequently hapj)ened that an examination by one 
familiar with the characteristics of ticks has shown that those found 
on such cattle and supposed to have been fever ticks belong to another 
species that is entirely harmless as regards transmitting Texas fever. 

All the investigations regarding the life history of the Texas-fever 
tick show that although the young, or larva^, may live for a long time 
on the ground without a host, they can not mature except as parasites 
on the bodies of cattle, or, less frequently, of horses, mules, and asses. 
And statements claiming that the adult ticks of this species have been 
observed to develop in localities where their absolutely necessary hosis 
have never been are erroneous, resulting from the confusion caused by 
the similarit}' in appearance of the cattle tick to the harmless ticks. 
It therefore becomes merely a question of recognition, and the follow - 
ing short descriptions, taken principally from Salmon & Stiles's paper 
(m *' Cattle ticks,'' are furnished to assist in recognizing the fever tick 
and in distinguishing it from others that may be observed on cattle. 

There are eight species of ticks which have been found on cattle in 
rhis country, but the first six mentioned are by far the most common. 
They all show the same successive stages of development, namely, 
eggs, larvae or seed ticks, nymphs, and adult male and female ticks. 
Those parts of the adult female tick which will be described below 
are the head and adjacent shield — which together have erroneously 
been termed the head parts — and the back of the body, since these 
portions of the parasite furnish features which to the naked eye are 
the most readily distinguished by cattle owners. .Much stress can 
not be laid upon the color of these various ticks, as it changes con- 
siderably with age. In the adult stage they all have four pairs of 
legs, varying in length and slenderness according to the species, 
but these differences are not sufficient to separate one species from 
another. 

Boophilus annulatus {Texas fever, or cattle, tick). — Plate 1, figure la, shows 
the natural size of an adult female Texas-fever tick, whose characteristic 
markings are better brought out in figure 1. magnified four times. a This tick may 
be readily distinguished from the other seven ticks by the small size and the 
color of the head and shield, the so-called head parts, whose lateral borders 
are straighter and more parallel, as shown in figure lb. These head parts are 
short and relatively broad and dark reddish brown or chestnut brown in 

a In each of Plates 1 and 2 there are shown ( 1 ) the natural-sized mature 
female tick, (2) this tick magnified four times, and (3) the head and shield of 
the same enlarged ten to fifteen times. ^ 



14 BUREAU or' ANTMAL INDUSTRY. 

color, appearing as a convex plate on the median line at the fore end of the 
tick. The body is oblong oval in shape and may reach * inch in length. The 
color varies from a dull yellow to an olive brown; often it is mottled with 
irregular areas of yellow and brown or streaked with wavy lines of these 
colors. Two grooves or indentations are seen running from the front to the 
rear on the skin of the back, which become almost, if not entirely, effaced at 
about the middle of the body. Another groove is seen between these two grooves 
in the posterior half of the body. These grooves are caused by the contraction 
of the muscles of the body and therefore vary considerably, entirely disappear- 
ing when the tick is full of blood. They are very distinct when the ticks have 
been removed from cattle several days. The four pairs of legs are brown, 
moderately long, and very slender. This tick is found principally on cattle, 
less frequently on horses, mules, and asses, and in one case it was found on a 
deer. The Federal quarantine line indicates the northern boundary of the sec- 
tion of the United States infested with fever ticks. 

Ixodes ricinus (castor-bean tick). — The body of this tick (PI. 1, figs. 2 and 2a) 
resembles in shape that of an eggplant, and it takes its name from its similarity 
It) the bean of the castor-oil plant. It is lead-colored, with a variegated mixture 
of yellowish red, brown, or gray. The body contains two anterior grooves that 
slightly diverge from each other, and three posterior" grooves, the middle one of 
which is straight, while the other two are curved outward. The mature female 
is from f to ^q inch long and has four pairs of dark-brown thin legs. The 
head and adjacent shield are a shiny dark brown or a chestnut brown, the latter 
portion being five-sided, like a pentagon (fig. 2b), with lateral borders prominent 
and rear angle rounded. Two stout and well-developed feelers (palpi) may be 
seen extending outward on each side of the head. This tick has been collected 
from sheep, cattle, goats, horses, deer, dogs, cats, foxes, rabbits, birds, man, and 
a few other animals. It was one of the first ticks studied, and has a very wide 
distribution in the United States. 

Dermacentor reticulatus (net tick). — The body of the adult female tick is 
oblong oval, f inch long, and of a deep brown. or slate color (PI. 1, figs. 3 and 
3a). It has four pairs of brown legs of moderate length. The skin of the 
back and head is covered with fine points, or punctations, which almost dis- 
appear at this stage. Besides the grooves that are located like those in the 
cattle tick, there is a marginal groove extending around the body just inside 
the border. There are also eleven small indentations (festoons) arranged 
about the posterior margin of the body. These festoons and grooves become 
shallow or effaced in the adult stage. The shield portion of the head i^arts 
has a silvery white metallic rust extending along the two sides and posterior 
portion (fig. 3b). It may have a rose or greenish tinge. The head is larger 
than that of the cattle tick. The net tick has been found on man, cattle, 
horses, sheep, and deer ; and in this country it seems to be most common in 
the West, especially in California, Texas, and New Mexico. 

Dermacentor electus (American dog tick: also called wood tick). — This tick 
(PI. 1, figs. 4 and 4a) resembles the net tick (Dermacentor reticulatus) so 
closely that a hand lens must be used to distinguish between them. However, 
it can be readily known from the Texas-fever tick by the fact that the so-called 
head parts are longer and broader (fig. 4b). Here there is also a yellowish 
white rust in the posterior portion which extends anteriorly along each side 
as two bright, iridescent lines separated hy a central brownish area. The 
bodj^ is oblong oval in shape and measures as much as f inch in length. 
The skin of the back contains grooves like those found in cattle ticks, and, in 
addition, another groove extending around just inside the margin, together 
with eleven smaller grooves (festoons) on the posterior border. These lines, 



TEXAS FEVETJ AND TTS PREVENTION. 15 

so distinct in the young female, become shallow at maturity. This tick has 
been found on man. cattle, dogs, horses, rabbits, and panthers, and has been 
collecfed in woods and on uncultivated lands in many sections of this country, 
especially in eastern United States. 

AmhJijonnna americanum (Lone Star tick). — As is indicated by figures 1 and 
la of Plate 2. the body of this tick is oblong oval and of a yellowish gray or 
l>rown color. The skin is rough and puckered unless the body is full of blood. 
The reddish brown area at the front of the tick is composed of the head and 
head shield. The latter extends backward a short distance to form a triangle, 
in the apex of which is a white or metallic yellow spot from which it derives 
its name "Lone Star" (tig. lb). The mature female may reach ^ inch in 
length and has four pairs of long thin legs. This tick has been found on cattle, 
dogs, horses, sheep, and man. and is very widely distributed in the United 
States. 

OrnitJiodoros megniul (ear tick). — As will be observed from figures 2 and 
2a. Plate 2, the shape of this tick is similar to that of the body of a violin. It 
is nearly twice as long as broad, rounded at both ends, narrower behind than 
in front, and slightly constricted in the middle. In color it varies from gray 
or brown to violet, and has two grooves behind the head, with a middle one in 
the posterior portion. On the skin of the back are numerous minute spines, or 
stiff hairs. The adult females are from i to f inch in length, and have four 
pairs of long stout legs. The anterior portion of the tick is curved downward 
to form a cover for the very small and short head, which can only be seen from 
the under side of the tick. The feelers (palpi) and beak, however, stick out 
from under the front part of the body and can be seen from above (fig. 2b). 
This tick is found in the ears of cattle, horses, mules, asses, and other animals 
in the South and West. 

Argas niiuiatus {chicken tick). — In shape and appearance this tick is like an 
enlarged bedbug, and is of a uniform reddish brown color, with four pairs of 
lighter colored legs. The skin is wrinkled and contains very short and minute 
hairs. On the top as well as the bottom of the tick are numerous bright pits 
or cavities with raised borders (PL 2, figs. 3 and STa). These vary in size, 
are arranged in rows radiating from the center more or less uniformly, and are 
usually symmetrical on each side. It is about f inch in size when mature. The 
head is so completely covered by the body that it can not be seen from tlie back 
(fig. 3b).. This tick has been observed on cattle once only, but is frequently 
found on chickens, turkeys, and other birds in the South. 

/.ror/cs hc.ragoinis {Enrot>ca}i (log tick). — The body of this tick is oval in 
shape and of an asliy color (PI. 2. figs. 4 and 4a). The grooves on the back 
are united in an arch in front and diverge in the posterior portion of the body. 
The four pairs of legs are longer, thicker, and stronger than those of the cattle 
tick. The head and shield are brown-red in color and similar in shape to those of 
the castor-bean tick, but less oval and rather more lozenge-shaped, with more 
acute lateral angles and narrower posterior angle (fig. 4b). The palpi, or feel- 
ers, are longer and more prominent than in the cattle tick, but not so long as in 
the castor-bean tick. This dog tick has been collected from dogs, cattle, sheep, 
foxes, rabbits, squirrels, gophers, cats, birds, man, and other hosts in eastern 
Ignited States. 

SOME OBJECTIONS TO THE ROLE OF TICKS AS CARRIERS OF TEXAS FE\'ER, 

WITH EXPLANATIONS. 

Texas fever in animals apparently not infested with ticks. — One 
objection that has been advanced against the fact that the cattle 
tick is a carrier of Texas fever is that cattle are sometimes found to 



16 BUREAU OF ANIMAL INDUSTRY. 

be suffering with the disease without showing the presence of the 
ticks on their bodies. This condition, in case of Southern ^^attle, 
may be explained on the hypothesis that the animal already had its 
blood infected with the microparasites and under normal conditions 
was immune from Texas fever; however, as a result of lowered 
vitality caused by some other disease, or by exposure, privation, 
injury, rough handling, etc., this immunity has become reduced and 
finally overcome, and the parasite of Texas fever, dealing now with 
an impoverished condition of the animal, succeeds in producing 
Texas fever. Since the experiments of this Bureau show that the 
blood of an immune animal may contain this microparasite for at 
least thirteen years after removal from all sources of infection, it 
would appear that this recurrence of disease in immune animals 
placed under adverse conditions could occur at almost any period of 
their lives, and may be termed a relapse. Thus it has been fre- 
quently noted that Southern cattle, born and raised in infected pas- 
tures but later freed of ticks and placed on noninfected soil, have 
died of Texas fever when their health was so weakened as to permit 
the parasites already infecting the blood to overcome the natural 
resistance of the body, and produce the disease. 

Again, in certain dipping experiments where the animals had been 
roughly handled and unduly, exposed after having been dipped in a 
severely irritating solution, a few deaths occurred from Texas fever 
among cattle which were known previously to have been immune — 
tick-infested Southern animals — but whose vitality had been reduced 
through these extraordinary conditions. 

On the other hand, when this disease is observed in Northern ani- 
mals, the young seed ticks may be so small and so few in number as 
to be passed readily by even a careful examination, yet numerous 
enough to cause the affection. In svich cases the proof will be found 
either by prolonged search or in the fact that other animals subse- 
quently take the disease with larger ticks apparent on the skin. 

Southern cattle infested with fever ticks may die of Texas fever. — 
When cows born and raised in the South die of Texas fever, it is 
proof that such cattle never came in contact with infected cattle 
ticks before, or that they were raised on tick-free pastures, or tliat 
they belong to those cases of immune Southern cattle which lose 
their immunity when subjected to adverse or extraordinary condi- 
tions, such as those mentioned above. Otherwise they would have 
been unsusceptible and w^ould not have developed Texas fever. 
Southern cattle, when raised and kept in districts free from cattle 
ticks, fail to secure the natural immunity induced by gradual and 
constant tick infestation from birth, and they are just as susceptible 
to the disease as are Northern animals. Under certain conditions, 
as when living on horses, mules, etc., fever ticks lose their infectious- 



V-'^ 



DESCRIPTION OF PLATES. 

PLATE 1. 

Fkj. 1. Mature female cattle tick (X 4). 

la. Mature female cattle tick (natural size). 
lb. Head and shield of same (X 15). 

2. Mature female castor-bean tick ( X 4). 

2a. Mature female castor-bean tick (natural size). 
2b. Head and shield of same (X 15). 

3. Mature female net tick (X 4). 

3a. Mature female net tick (natural size). 
3b. Head and shield of same (X 15). 

4. Mature female dog, or wood, tick (X 4). 

4a. Mature fem.ale dog, or wood, tick (natural size). 
4b. Head and shield of same (X 15). 

PLATE 2. 

Fig. 1. Mature female Lone Star tick (X 4). 

la. Mature female Lone Star tick (natural size) . 

lb. Head and shield of same (X 15).. 

2. Mature female ear tick ( X 4). 

2a. Mature female ear tick (natural size). 

2b. Head of same protruding from beneath ( X 15). 

3. Mature female chicken tick ( X 4) . 

3a. Mature female chicken tick ( natural size ) . 
3b. Upper portion of same, head invisible (X 10) . 

4. Mature female European dog tick ( X 4). 

4a. Mature female European dog tick (natural size). 
4b. Head and shield of same (X 15). 

PLATE 3. 

Fig. 1. Larva of cattle tick (X 25). 

2. Larva of cattle tick (natural size). 

3. Mature female and eggs ( natural size ) . 

4. Hide showing cattle ticks (natural size). 

5. Blood cells containing Texas fever protozoa ( X 1,000), 

6. Male cattle tick (X 15). 

7. Male cattle tick (natural size). 

8. Young female cattle tick (X 15). 

9. Young female cattle tick (natural size). 

10. Various stages and colorations of cattle ticks. 



Bull. No. 78, B. A. 1. 



Plate 1 . 




Haines, del. 



A.Hoen &Co.,Litho. 



VARIOUS TICKS THAT INFEST CATTLE. 



Bull. No. 78, B. A. I. 



Plate 2. 




Haines, del. 



A Hoen&Co.,Lii 



VARIOUS TICKS THAT INFEST CATTLE. 



Bull. No. 78, B. A. I. 



Plate 3. 






10. 



^■% 



f If 



HaiTieS,del. - A.Hoen &Co.,Litho 

TEXAS FEVER PROTOZOA AND THE TICKS WHICH TRANSMIT THEM. 



TEXAS FEVER AND ITS PREVENTION. 17 

ness. and when Southern cattle not previously infested with any but 
these noninfected ticks conw in contact Avith infected ticks they are 
just as susceptible as cattle raised on tick-free pastures, as indicated 
below. 

Harmless ticA's mistaken for Texas- fever' ticks. — A very prolific 
cause for argument against the relation of ticks to Texas fever has 
been the confusion which exists with reference to the various species 
of ticks observed on cattle. Some stockmen have claimed that ticks 
will not cause Texas fever, because their experience has not been 
Avith the Texas- fever ticks, but with the species of ticks described in 
the preceding pages, which are harmless so far as their ability to 
transmit Texas fever is concerned, or with the noninfected cattle 
ticks mentioned below. A similar experience with these harmless 
ticks upon woodland far removed from cattle and confusing them 
with cattle ticks have led others to claim that it would be impossible 
to eradicate the latter from infested pastures. However, their life 
histories are not parallel, since the cattle ticks demand the blood of 
cattle or equines in order to mature, while the ear, dog. Lone Star 
ticks, and others do not. Thus, if the fever ticks can be separated 
from these animals for a definite period they will die from lack of 
a host. 

Susceptible animals having fever ticks icithout Texas fever. — In 
rare cases it has been observed that certain Texas-fever ticks do not 
contain the protozoan of Texas fever, and when such ticks fail to 
produce disease in susceptible animals some persons have been led to 
argue that none of this species will transmit the infection. Texas- 
fever ticks without the virus of Texas fever in their bodies are termed 
noninfected ticks. They may haA^e lost their infectious property by 
liA'ing on a nonsusceptible animal, such as a horse, mule, ass, or suck- 
ing calf, as experiments have shown that a generation of infected ticks 
on these animals Avill eliminate the infection from their bodies and, 
when the next generation of seed ticks is placed on susceptible cat- 
tle, no disease is produced. These ticks Avill become reinfected, how- 
CA^er, if allowed to infest Southern cattle containing the Texas-fever 
protozoa in their blood. N^oninfected cattle ticks are so A^ery uncom- 
mon that they are the exception, and since the A^ast majority are 
dangerous it would be aclAdsable to treat all cattle ticks as infected and 
capable of transmitting Texas feA^er . 

Fever ticks on other animals without producing disease. — The rea- 
son that Texas-feA^er ticks can remain on animals other than cattle 
Avithout producing the disease is because these animals are not sus- 
ceptible to Texas fcA^er. Numerous experiments haA^e shoAvn that 
only bovines contract Texas fcA'er, so it is not difficult to understand 
why other hosts can be infected Avith impunity. 
10679— No. 78—06 m 3 



18 BUREAU OF ANIMAL INDUSTRY. 

OTHER INJURIOUS EFFECTS OF CATTLE TICKS. 

Many cattle owners who have always been accustomed to see both 
ticks and ticky cattle on their farms are unfortunately not inclined 
to attach nnich importance to cattle ticks, and, as a rule, through 
lack of appreciation of their damaging effects, placidly consider them 
as of little consequence. That ticks may be detrimental to their hosts 
ill several ways has probably not suggested itself to these stockmen, 
who are most vitally affected, and it therefore seems necessary to 
emphasize the fact that, in addition to their relation to Texas fever, 
they may also be injurious to cattle as external parasites. AVhile 
the power of transmitting Texas fever is undoubtedly the most dan- 
gerous property possessed by the cattle tick and is the principal 
cause for adopting stringent measures in securing its complete eradi- 
cation, nevertheless there still remain other good reasons for the 
accomplishment of this achievement. These secondary objections to 
the presence of ticks on cattle consist in the physical harm they do 
to the host aside from the production of the specific disease of 
Texas fever. True, a few parasites may remain on cattle indefinitely 
without causing any noticeable effect, but it is not uncommon to 
notice bovine animals on pastures with their hides heavily infested 
Avith these pests. In such cases it can readily be seen that the contin- 
uous sucking of blood causes more or less impoverishment of the 
circulation. The animal must therefore be fed heavier in order to 
meet the demands of the parasites in addition to the ordinary needs 
of the host. If the ticks be removed from the body, the bites inflicted 
are often distinguished by small inflamed or reddened areas some- 
what swollen, with perforations of the skin which may allow the 
entrance of various kinds of disease germs, and showing that more 
or less irritation of the hide is produced by these parasites. This 
condition, together with the loss of blood, frequently induces an irri- 
table state and evidences of uneasiness commonly known as " tick 
worry," which results in the loss of energy and other derangements of 
the animal's health. It may in some cases become so pronounced, 
especially in hot weather, that the animal will lose flesh in spite of 
good pasturing, thereby reducing the vitality and rendering it more 
susceptible to the inroads of disease. Moreover, if the infestation of 
ticks is not controlled, the cattle may be so reduced in condition that 
growth is retarded, and, in the case of young animals, they may never 
become fully developed, but remain thin, weak, and stunted — a con- 
dition that has been termed " tick poverty " — and easily succumb to 
other diseases as a result of lowered vitality. In milch coavs this 
debilitating influence of the numerous ticks is shown in a greatly 
reduced milk supply. This should not appear strange when it is con- 
sidered that some animals harbor several thousand of these blood- 



TEXAS FF.VER AND ITS PREVENTION. 19 

sucking parasites. If these parasites are crushed, it will be found 
that their intestines are comi)letely filled with a dark, thick mass of 
blood abstracted from the animal host and containing nutriment that 
should go to the formation of milk, flesh, and the laying on of fat. 
In some rare cases the large number of bites over a limited area of 
skin may be followed by infection with pus-producing organisms, 
giving rise to small abscesses which ma}^ terminate in ulcers. The 
discharge from such sores, or in some cases the mere oozing of blood 
serum through the incision made by the mouth parts of the ticks, 
keeps the hair moist and matted together, and the laying and hatch- 
ing of fly eggs in these areas give rise to infestation Avith destructive 
maggots, causing ulcers and other complications that require medical 
treatment. These statements regarding the secondary injurious 
effects of cattle ticks also apply to those ticks which have been pre- 
viously spoken of as harmless in so far as Texas fever is concerned, 
and, in fact, to all external parasites. Therefore, it is just as impor- 
tant to eradicate the cattle ticks for reasons other than those associ- 
ated wdth Texas fever as it is to exterminate lice, fleas, and other 
A'ermin. Furthermore, cattle ticks, aside from the losses sustained 
])y their purely parasitic effects, are the greatest menace to the profit- 
able raising and feeding of cattle in the South, because they are an 
obstacle to cattle traffic betw^een the infected and noninfected districts. 

LOSS OCXASIOXED BY CATTLE TICKS. ' 

The economic aspect of the tick problem is unquestionabl}^ of the 
greatest practical interest, since the fundamental importance of all the 
other questions which surround it depends upon the actual money 
A^alue iuA^plved. It would therefore seem advisable to furnish a fcAv 
statistics showing the financial loss sustained by the country as a 
result of the presence of this parasite. It is w^ell known that those 
animals, coming from an infected district and sold in the " southern 
pens " of northern stockyards, bring an aA^erage of one- fourth to one- 
half a cent less per pound than the quoted market price. The handi- 
cap that is placed on the southern cattle raiser as a result of this 
decrease in value of his stock Avill average at the former figure at 
least $1.50 per head, allowing an individual w^eight of 600 pounds for 
all classes of animals, so that the loss on the estimated 705,000 
southern cattle, including stock, beef, and dairy animals, marketed 
yearly under these conditions Avill s\Tm up a loss of $1,057,500 per 
annum. Carrying this estimate still further it Avill be found that this 
decreased value reacts and fixes the A^aluation of all cattle Avhich 
remain in the infected territory, thereby reducing the assets of the 
cattle industry of that section b}^ this ratio per head for the four and 
a half millions of cattle east of the Mississippi River and the eleA'en 



20 BUREAU OF ANIMAL INDUSTRY. 

millions of cattle west of the Mississippi River; or, altogether, the 
enormous shrinkage in vahie of $23,250,000 directly chargeable to the 
cattle tick. This sum, however, should not be considered in determin- 
ing the yearly devastation caused by the cattle tick, but rather as an 
unnecessary reduction in the assets of the infected country. .This last 
loss does not include the decrease in flesh and lack of development of 
southern cattle occasioned by the parasitic life of the ticks from with- 
out and b}^ the blood-destroying and enervating properties of the 
protozoan parasites from within, an additional loss which is so very 
great that a conservative estimate Avould place it equal to the loss 
above mentioned, or $23,250,000. 

The shrinkage in the milk production of cattle harboring many 
ticks will average 1 quart per da3^ and the loss occasioned thereby at 
3 cents per quart for the 875,000 ticky dairy cattle out of more than 
4,000,000 dairy cattle below the quarantine line would amount to 
$26,250 per day, or, counting three hundred milking days for each 
cow to the year, $7,875,000 per annum. The damage resulting to the 
southern purchaser of northern purebred or high-grade cattle is 
another item of no small moment. About 10 per cent of all such cattle 
taken South die of Texas fever even after they are immunized by 
blood inoculations, and about 60 per cent of these cattle succumb to 
Texas fever when not so treated. Since they are usually very expen- 
sive animals and of a highly valued strain of blood, the loss in certain 
cases is excessive and in others almost irreparable owing to the possi- 
ble extinction of some particular type especially selected for the 
improvement of the herd. Thus of the approximate 4,600 of such 
cattle brought South each year, at least 460 die of Texas fever. The 
loss entailed would naturally depend on the value of each animal, and 
since the prices paid for such well-bred cattle range from $100 to 
$1,000 or even more, it can readily be conceived that the yearly loss 
from this item alone varies from $46,000 upward. 

Another instance where it is difficult to figure the injurj^ done by 
the ticks is in the case of death of nonimmune cattle in the tick- free 
pastures of the South. Such animals are as susceptible to Texas 
fever as nonimmune northern cattle, and, inasmuch as there are in 
many States only one out of every four farms infested w^ith ticks, 
the cattle on the remaining farms will in many cases contract Texas 
fever when exposed to the fever tick. These losses can scarcely be 
computed, as the death rate depends so much on the season of the 
year when exposure occurs and on the age of the animal affected. 
However, the deaths among such cattle are considerable, although 
this fact is little appreciated or understood by many outside of the 
infected area. Thus, if we consider one-tenth of the cattle below 
the line as nonimmunes which contract the disease on exposure to 
ticks, and if we figure on the death rate of 25 per cent of these 



TEXAS FEVER AND ITS PREVENTION. 21 

animals — a conservative estimate — the loss Avould amount to 887,500 
animals, which, at an estimated value of $15 ])er head, would amount 
to a loss of $5,812,500 per annum. And this sum, excessive as it 
may seem, represents a smaller percentage of loss on the total valu- 
ation of neat cattle than has been' determined by several of the 
infected States. 

On rare occasions a small outbreak of Texas fever occurs north 
of the quarantine line as a result of improperly disinfected cars, of 
unscrupulous dealers breaking the quarantine regulations, or of 
some accidental condition. Such damage, however, is slight, but 
should be given consideration in summing up the loss occasioned 
by the fever tick. 

The advertisement which a breeder obtains and the sales which are 
made by having his stock in the show ring are usually lost to the 
southern cattle raiser who aspires to display his animals in the 
Xorth, as they are barred from most of these exhibitions. On the 
other hand, the southern farmer is not given an opportunity to see 
and be stimulated by the fine specimens of northern cattle which 
might be shown at southern stock exhibits, for the reason that the 
danger of contracting Texas fever is too patent to w^arrant such 
exposure. The expense incurred by the Government in enforcing 
the regulations that apply to the quarantine line reaches about $42,000 
per annum, while the cost to the various States for similar Avork 
along their individual quarantine lines amounts to a very modest 
sum in some States, but to large figures in others, aggregating about 
$28,000 yearly. 

Another loss which is indirectly sustained by the southern cattle 
industry through increased freight rates is the cost to the railroad 
companies of cleaning and disinfecting the cars that carry southeriA 
cattle and in providing separate pens for these animals at various 
locations. This sum may be calculated at not less than $29,000 per 
annum. 

If all the above-mentioned losses are added it will be found that 
the Texas-fever tick is responsible for about $40,000,000 of loss an- 
nually to the people of the infected country, and that it also lowers 
the assets of the South by an additional $28,250,000. These figures 
are not given as accurate in any particular, but they are sufficiently 
close to indicate that the loss to the quarantined section from the 
cattle tick is something enormous and represents about 16 per cent of 
the total valuation of the cattle in that region. It must be admitted 
that this is by far too great a barrier to the successful operation of any 
business. Such a series of encumbrances as those recorded could be 
carried by the cattle industry of no other section of the country but 
the South, whose excellent pastures, rich soil, and salubrious climate 
are the only reasons for its ability to overcome such obstacles in meet- 



22 BUREAU OF ANIMAL INDUSTRY. 

iiio- the competition of the West. And it is the inherent capacit}^ of 
the South for greatl}^ increasing its herds and enlarging its pasture 
lands that makes the actual loss even secondary to the potential loss 
due to restrictions necessitated by the presence of the cattle tick. 
This potential loss may be described as the difference between the 
value of the cattle industry of the South to-day and the extent to 
which this industry would be increased if farmers and ranchmen 
were assured that their lands and cattle would not become infested 
with fever ticks. Could this assurance be given the beneficial effects 
would extend over the entire country, because the market of the 
northern breeder would thereby become greatly extended. 

These appalling losses and annual sacrifices of the cattle raisers of 
the infected district can be entirely effaced, and this at a small pro- 
portionate cost; for, with enthusiastic stockmen, satisfactory State 
legislation, sufficient money, and a trained corps of inspectors, the 
cattle tick may be exterminated, and every dollar expended in this 
work will be returned man}^ fold during each succeeding year. 

PERIOD or DEVELOPMENT OF DISEASE AFTER EXPOSURE TO TICKS. 

The length of time elapsing between the exposure of susceptible 
cattle to the cattle tick and the appearance of Texas fever among 
them is dependent upon the climate and the development of the ticks 
to which they are exposed. Thus, if any Northern animals are placed 
upon pastures, highways, or in pens, cars, etc., in summer immedi- 
ately after the premises have been infested with ticks from Southern 
cattle, Texas fever may occur in from thirty to sixty days, as the 
females that drop from the Southern cattle must lay eggs and these 
must hatch before the Northern animal becomes infested with ticks, 
and thereby inoculated with the disease. In cool weather this period 
may extend to ninety days, as it takes much longer for the eggs to 
hatch. Where Northern animals are not exposed in an infested pas- 
ture until the ticks which fell from the Southern cattle have laid eggs 
and the larvae, or seed ticks, are already present, the former cattle will 
develop symptoms in thirteen to fifteen days in hot weather. Thus 
under natural conditions the disease appears in thirteen to ninety 
days after exposure. After the seed ticks become attached to the 
animal the disease will appear in about ten days in summer, and after 
a somewhat longer period in cooler weather. In fact, the disease may 
occur before the ticks are large enough to be seen without a very care- 
ful search. By artificially inoculating a cow^ under the skin or into a 
vein with virulent blood the disease may be produced in three to ten 
days. 

SYMPTOMS. 

The symptoms of Texas fever present two distinct types, depending 
upon the time of year the disease makes its appearance and the sus- 



TEXAS FEVER AND ITS PREVENTION. 23 

ceptibility of the animals attacked. These types are spoken of as thi^ 
acute and chronic forms of the disease. The acute, fatal form is 
seen when nonimmune Northern cattle and the susceptible Southern 
animals raised on tick-free pastures are attacked in the hot summer 
months. The milder, chronic form, usually nonfatal, occurs when 
noninnnune cattle are affected in the late autumn and in the partially 
immune cattle beloAA^ the Texas-fever quarantine line at all seasons 
of the year, the latter animals usually not being attacked by the acute 
form of the disease. 

Acute type. — In this form of the disease the temperature rises 
within twenty-four to forty-eight hours to 107° or 108° F., and the 
animal rapidly shows signs of being affected with a severe malady. 
It is depressed, leaves the herd, and lies down or stands off by itself 
with head lowered, ears dropped, feet drawn together, and back 
arched from the pain in the liver and kidneys. If the nature of the 
disease is suspected, the rise of temperature may be ascertained by 
the use of the thermometer or by merely placing the hand about the 
root of the tail or between the thighs. The muzzle is dry, the appe- 
tite lost, and rumination ceases. Constipation is always present 
during the first stages of the disease, but it frequently gives place 
later to diarrhea, and the manure is usually heavil}^ stained with bile 
and in rare cases may be mixed Avith blood. Accompanying the rise 
of temperature, as in all other acute febrile diseases, there is an in- 
crease in the rate of respiration and pulse beat. The former may 
rise to from 50 to 90, Avhile the latter varies from 90 to 120 per minute. 

The changes Avhich occur in both the urine and blood are extremely 
important, but the urine will receive first consideration here, as it is 
more readly examined by the la3^man than the blood. The pecul- 
iarity of the urinary secretion is that it is blood-stained — the so- 
called hemaglobinurea — from Avhich symptom the disease has de- 
rived its name of "" red water." The protozoa in the circulation 
break up the red corpuscles, liberating the substance hemagiobin, 
Avhich is the coloring matter of the blood. This substance being 
free in the blood plasma is excreted by the kidneys, giving the urine 
its red color, Avhich is so characteristic of Texas fever. This dis- 
coloration of the urine is present in the majority of the acute cases, 
but it is frequently wanting in the chronic form of the disease. The 
color A^aries greatly from a mere pinkish tint to an almost black 
color, depending on the rapidity of destruction of the red cells and 
the excretion of the coloring matter through the kidneys into the 
urine. There is also a small quantity of albumen in the urine of 
the majority of cases. The comparative weight (specific graAdty) of 
the urine, which in the beginning stages is increased (1,028 to 1,040), 
is later reduced to normal (1,010 to 1,020). 

The blood also furnishes great assistance in making a diagnosis 



24 BUREAU OF ANIMAL INDUSTRY. 

of suspected Texas fever, and the finding of tlie intracorpuscular 
parasite microscopically is conclusive evidence. This fluid, as it 
oozes from a small incision in the skin, is pale and watery, indicative 
of great reduction in the cellular element, and is readily seen to 
differ markedly from the normal red blood of healthy animals. 
Sometimes there is such a lack of blood in the vessels of the skin 
that a very deep incision has to be made in order to obtain sufficient 
blood for inspection. It is also at times noted that the power of 
coagulability of the blood is so reduced that when it once starts to 
flow it is only after a considerable time — or by applying pressure — 
that the hemorrhage is stopped. In the majority of cases, however, 
the tendenc}^ of the blood to clot is unaffected. 

Cerebral s^aiiptoms are noticed in a certain percentage of cases 
Inanifesting themselves in the form of staggering gait, disturbances 
of vision, or delirium. There is in milch cows a reduction or a com- 
plete stopping of the milk secretion. Abortion is also very common 
in pregnant animals. Death usually occurs within three or four days, 
and is generally preceded by a marked fall of body temperature to 
normal or even subnormal a few hours before the fatal termination. 
In nonfatal cases the temperature falls gradually after the crisis and 
soon reaches the normal, but recovery is prolonged over weeks and 
even months, as a great deal of time is required to regenerate the 
greatly impoverished blood. 

Chronic type. — This form of the disease appears under natural 
conditions usually in the late autumn and early winter. It can be 
produced experimentally, however, by placing a few ticks on the skin 
of a susceptible animal — a fact of ver}^ great importance in the pro- 
duction of immunity against the acute type among Northern cattle. 

This form shows all the symptoms of the acute type, but in a milder 
degree. The temperature usually remains about 103° and neA^er 
exceeds 105° F. There is loss of appetite, stoppage of rumination, 
constipation, and albumen in the urine. An anemic condition of the 
blood, as indicated by the pale and bloodless mucous membranes, is 
also present, but hemaglobin is not usualty excreted by the urine, 
hence the red-water symptom is absent. There is also excessive loss 
of flesh and, before the end of the attack, the affected animal is greatly 
emaciated ; although death rarely occurs the valuation of the animal 
is much reduced. 

Relapses. — Following recovery from an acute attack, when the red 
blood corpuscles have apparently reached their normal number, there 
has frequently been observed a relapse or recurrence of the disease in 
the mild, chronic form, accompanying which there is a second period 
of destruction of the red cells. This follows within three to six 
weeks after the symptoms of the acute attack have subsided. For a 
considerable time it was unknown wli^ether this was a relapse of the 



TEXAS FEVER AND ITS PHEVENTTON-. 25 

acute attack or due to reinfection from a second aeneration of ticks. 
Smith and Kilborne, however, proved that it could occur as a relapse 
without the 2:>i*esence of ticks, but it may also in some cases be caused 
by a second extraneous infection. 

APPEARANCE AFTER DEATH. 

The postmortem examination should be made as soon as possible 
after death, as the carcass of an animal dead of Texas fever under- 
goes decomposition very rapidly. The skin should always be first 
examined for the presence of the cattle tick, as the discovery of any 
of the forms of this parasite on the skin of the escutcheon, thigh, or 
belly leads at once to a suspicion of the presence of the disease. The 
skin is usually normal in appearance, no visible alterations being 
present except possibly the small swellings, minute hemorrhages, and 
perforations from the bites of the ticks. Upon cutting into the hide 
and skinning the carcass, a marked lack of blood in the blood vessels 
of the skin and underlying tissues is observed. Occasionally there 
may be noted a yellowish, jaundiced discoloration of these tissues. 
The fatty tissues are also yellowish, and, instead of possessing the nor- 
mal firm consistency, they are soft and oily. In very severe cases, 
even the muscular system ma;y have a jaundiced appearance. This 
discoloration is due to the alteration of the bile-secreting function of 
the liver, but is by no means present in all cases, being most constant 
in the acute, rapidly fatal form of the disease. 

Probably the most marked pathologic alterations in the disease 
are found in the liver. This organ is very much enlarged and has 
a yellowish, mahogany-brown color, due to the bile it contains. This 
secretion becomes excessive, and minute plugs of congealed bile form 
in the small bile ducts, thus stopping them and damming the bile 
in the organ, which produces the yellowish color. This does not 
occur evenly throughout the organ, and consequently it has a mottled 
appearance. The gall bladder is usually distended with bile, and its 
mucous membrane often contains numerous minute hemorrhages or 
petechial spots. The bile is very thick, has the appearance of 
" chewed grass," and contains numerous firm, irregular flakes. The 
spleen also shows marked pathologic alterations. Normally this 
organ weighs from 1| to 24 pounds, but in cases of Texas fever it is 
enormously enlarged, sometimes reaching four times its normal dimen- 
sions. It is very dark at times, almost black in color, due to the 
enormous accumulation of red corpuscles and hemaglobin within its 
substance. Upon cutting into the spleen, or merely attempting to 
pinch it up, the pulpy tissue will sometimes run out as a semifluid, 
blackish mass, due to the breaking down of its structures and to the 
excessive engorgement of the organ. 



26 BUREAU OF ANIMAL INDUSTKY. 

In death from the acute type of the disease the kidneys are usually 
found to be very dark in color and congested, and, on cross section, 
the normal markings are indistinguishable. The blood vessels are 
engorged with blood, and there is edematous infiltration of the sur- 
rounding fatty tissue. In the older, more chronic cases, the kidneys 
are paler and somewhat flabby. 

The bladder usually contains a varying quantity of urine, which 
may or may not be blood-stained. The mucous membrane frequently 
contains a few minute hemorrhages. 

No characteristic lesions are found in the stomach and intestines. 
There may be slight congestion of the third and fourth stomach, with 
slight peeling off of the epithelial lining. The intestines usually con- 
tain considerable bile and there is more or less edema of their walls. 
Blood effusions may have occurred from the walls of the gut, espe- 
cially in the rectum, producing a bloody discoloration of the feces. 
The large intestine also frequently shows severe congestion. None of 
these lesions, however, are constant, and the intestines furnish very 
little positive information in establishing a diagnosis. The lungs are 
rarely affected by the disease and, barring a slight edema, are found 
to be in a healthy condition. 

The membrane surrounding the heart (pericardium) frequently 
shows pin-point hemorrhages, as does also the membrane on the inner 
surface (endocardium) lining the walls of the heart cavities. The 
blood is observed to be paler and the clots softer than normal. 

COURSE AND TERMINATION. 

The course of the disease depends not only upon the time of the 
year the infection occurs, but also on the age, strength, and suscepti- 
bility of the animals attacked. When mature susceptible cattle con- 
tract the disease in the hot summer months, death usually occurs 
within a week — generally three or four days — after the first appear- 
ance of symptoms, but it may follow inside of twenty- four hours. 

In the late fall infections of nonimmune cattle and in the partially 
immune Southern cattle, however, the course of the disease is much 
more prolonged and covers a period of many weeks or even several 
months. In this type the continuous fever causes exhaustion, while 
at the same time the enormous destruction of red blood cells interferes 
very materially with the nutrition of the patient. As a natural con- 
sequence, emaciation becomes marked, and this, together with the 
poor appetite, leads to a fatal result in some cases. In the majority 
of cases, however, in spite of the severe alterations of the blood and 
internal organs, they begin after several weeks to show^ improve- 
ment. The temperature becomes normal and there is a tendency 
toward regeneration. This, however, requires weeks and months, the 



TEXAS FEVER AND ITS PREVENTION. 27 

animals in the meantime appearing weak and thin, having pale 
mucons membranes. Dnring the recnperative i)eriod the animal 
should by no means be fed excessively, as numerous cases of fatal 
gastro-intestinal disturbances have been reported from overfeediiig. 
The few animals which w^cover from the acute type of summer are 
quite likely to have a relapse in the form of the chronic type in the 
fall. 

The mortality in adult susceptible cattle, as the above statements 
readily show, may vary considerably, and ranges from 90 per cent in 
the months of July and August to less than 50 per cent in the late 
autumn and early winter. The prognosis must therefore depend 
on the time of year the outbreak occurs. In animals under 9 months 
of age, the course of the disease is usually short and the affection 
seldom fatal, while the death rate among 1-year-old cattle during the 
hot season is about 25 per cent, and less than 10 per cent in the fall 
and winter. Between 1^ and 2 years of age, the mortality is about 
double that at 1 year. 

INFECTIVE CHARACTER. 

Texas fever belongs to the group of infectious diseases, and it is a 
typical example of the few diseases of this class which do not com- 
bine the propert}^ of being contagious. It is infectious because it is 
due to the entrance and multiplication of a pathogenic microorganism 
within the body, but sick animals, in the absence of ticks, can remain 
in intimate association with healthy susceptible animals indefinitely 
without transmitting to them the disease, and hence it is not con- 
tagious. Furthermore, a coav perfectly healthy in appearance may 
contain in its blood the Texas fever protozoan, which, when trans- 
mitted to susceptible cattle by the fever tick, will produce the disease. 
It is certain that the piroplasma are present in varying numbers in 
the manure and urine of infected animals, and yet susceptible animals 
have never been known to become affected from grazing over tick-free 
pastures soiled with excrement from the sick animals. 

In 1890 the experiment was made by the Bureau of polluting a 
pasture with the blood and spleen of an animal dead of Texas fever 
and then allowing susceptible cattle to graze in the field for two 
months, but the animals remained perfectly healthy. Moreover, as 
has prcA^ously been stated, the feeding of ground-up ticks and viru- 
lent blood failed to produce the disease, showing that the digestive 
tract is proof against the infection. 

The disease therefore can be transmitted by three known methods 
only: (1) By the bite of the cattle tick; (2) by inoculating the 
blood of sick animals into healthy animals; (3) by inoculating the 
infected blood of apparently healthy Southern cattle into nonimmune 
cattle. 



28 BUREAU OF ANIMAL INDUSTRY. 

ANIMALS AFFECTED. 

Xiimerous experiments have been made on various species of ani- 
mals with highly virulent blood from cattle suffering with Texas 
fever, but the disease has been produced in bovines only. Among 
those animals that have failed to develop the disease after inocula- 
tion may be mentioned horses, asses, sheep, pigs, dogs, cats, mice, 
rats, guinea pigs, rabbits, chickens, and pigeons. All bovine animals 
that have iieA^er been exposed to the disease are susceptible to Texas 
fever, although sucking calves are so resistant as to be practically 
immune. Adult cattle are the most susceptible, and, if attacked in 
the summer months, usually die, Avhile in the fall and Avinter they 
more frequently recover. Cah^es under 8 months of age contract the 
affection in a very mild form, as a result of which they become im- 
mune from the disease. 

DISEASES MISTAKEN FOR TEXAS FEVER. 

There are two diseases of cattle which may be confounded with 
Texas fever. The differential diagnosis of the latter and anthrax is 
by far the more important, and it will therefore receive first consider- 
ation. Although these two diseases are frequently mistaken one for 
the other, there are numerous differences between them which, if care- 
fully considered and taken together, are usualty sufficient to establish 
a diagnosis. The following are the main features of Texas fever not 
found in anthrax : Young ticks are usually found on the hide of the 
affected animal; if occurring in the uninfected territory, the disease 
can invariably be traced to the shipment of Southern cattle into the 
country thirteen to ninety days previously ; young sucking calves are 
not affected; the mucous membranes become extremely pale and 
jaundiced, while in anthrax they are very red and congested; cattle 
onl}^ are attacked, while anthrax attacks all animals. Upon postmor- 
tem examination in Texas fever the tissues under the skin are very 
pale, Avhile in anthrax they are congested, with the blood vessels stand- 
ing out prominently. The blood is thin, pale, and w^atery, whereas in 
anthrax it is tarry, black, and incoagulable. The bile is semisolid 
and contains numerous hard flakes, wdiile in anthrax it is fluid. The 
spleen is affected quite similarly in both diseases, but the liver in 
Texas fever is enlarged, yellowish, and mottled from the plugging 
of the bile ducts, whereas in anthrax the liver, although enlarged, is 
very dark in color and is congested. 

It can usuall}^ be differentiated from blackleg by the fact that the 
great majority of victims of blackleg are between 6 months and 2 
years of age. There is usually a total absence of ticks on the hide in 
the latter disease, while there are present superficial crackling swell- 



TEXAS FEVER AND ITS PREVENTION. 29 

ings which on beino- opened are found to contain gas bubbles with 
the j^eculiar odor characteristic of the disease. There is also an ab- 
sence of blood-stained urine. On postmortem examination in black- 
leg the muscular tissues beneath the sw^ollen areas are very dark and 
soft, with bloody fluid, while the liver, spleen, and kidneys are appar- 
ently unatfected. 

TREATMENT. 

Medical treatment of the sick has generally been unsatisfactory, 
although in chronic cases and those occurring late in the fall bene- 
ficial results have folloAved. If the animal is constipated, a drench 
containing 1 pound of Epsom salts dissolved in 1 quart of Avater 
should be administered, followed by the sulphate of quinine in doses 
of 30 to 90 grains, according to the size of the animal, four times a 
day until the system is well saturated with it. Tincture of digitalis ^ 
ounce, and whisky or alcohol 2 ounces, may be combined with the 
quinine, according to indications of individual cases. An iron tonic 
containing reduced iron 2 ounces, pow^dered gentian 4 ounces, pow^- 
dered nux vomica 2 ounces, powdered rhubarb 2 ounces, and potas- 
sium nitrate 6 ounces will be found beneficial in the convalescent 
stage when the fever has run its course. This tonic should be given 
in heaping tablespoonful doses three times a clay in the food. Good 
nursing is essential in treating these cases. The animal should be 
given a nutritious laxative diet, with plenty of clean and cool drink- 
ing water and allowed to rest in a quiet place. 

If the stable or pasture is infested with ticks, the animal should 
be placed in a tick- free inclosuij, to prevent additional infestation 
Avith these parasites and the introduction of fresh infection into the 
blood. It is advisable, not only before but also during treatment, to 
remove from the sick cattle all ticks that can be seen, as they keep 
weakening the animal by w^ithdrawing a considerable quantity of 
blood, and thereby retard recovery. 

PREVENTION. 

It is generally accepted that if Southern cattle are entirely free 
from that species of tick know^n as Boophilus annulatus^ they can 
be allow^ed to mingle with the most susceptible animals without dan- 
ger. Furthermore, it has been learned from the study of the life his- 
tory of the cattle tick and from the fact that this tick infests pastures 
only transiently, never permanently, and w^ill not mature except 
upon cattle or equines, that its extermination is possible, and that 
the disease it causes may be prevented. The various methods w^itli 
these results in view^ should be directed tow^ard the destruction of 
licks on cattle as well as their eradication from the pastures. 



30 BUREAU OF ANIMAL INDUSTRY. 



HOW TO FREE CATTLE OF TICKS. 



Among the most important measures to be adopted in eradicating 
these parasites from cattle in the infested districts may be mentioned : 
(1) Picking or brushing them oii'; (2) smearing or spraying the 
animals with a disinfecting solution, and (3) dipping the " ticky " 
animals in a vat containing a solution capable of killing the ticks 
without injury to the cattle. 

The systematic application of one or more of these methods, to- 
gether with appropriate measures for eradicating or destroying the 
cattle ticks upon pastures, has been successfully adopted in certain 
sections, and has thus diminished the area of the infested district. 

Picking or hrusliing ticks off cattle. — Where the herd is small a 
very effective but laborious method is to pick off these parasites by 
hand or to scrape them off with a dull knife or a curr3^comb. This 
should be done at least three times a week in order to find all the 
adults before they mature and fall off, as by this system the smaller 
ticks which at first escaped detection will be found before they are 
fully developed. After removing the ticks they should be destroyed, 
preferably by burning. Care should be taken to go over all parts 
of the animal frequented by the ticks, especially under the belly, 
around the tail and udder, and inside the legs. After the ticks are 
picked or brushed off, the cattle should not be neglected, but should 
be carefully examined later for the presence of ticks wdiich have been 
picked up in the meantime. If this w^ork is Liioroughly performed 
and no ticks are allowed to fall off and lay eggs from June 1 to the 
end of November, the cattle will be free of ticks, and the pastures 
will have had an opportunity of be oming cleaned. 

Smearing or spraying cattle with a disinfecting solutio7i.^GveRsing 
the legs and sides of cattle with cotton-seed oil, fish oil, or Beaumont 
crude petroleum will assist in preventing the ticks from crawling up 
on the body. In small herds, smearing the cattle with a mixture of 1 
gallon of kerosene, 1 gallon of cotton-seed oil, and 1 pound of sulphur, 
or with a mixture composed of equal parts of cotton-seed oil and 
crude petroleum, or with Beaumont crude oil alone, has proved effi- 
cacious when applied to the skin two or three times weekly during 
the tick season. For this purpose sponges, syringes, brushes, mops, 
or brooms may be used. This method not only kills the older ticks 
on the cattle b}^ mechanically plugging up their breathing pores, but 
also makes the legs so slippery that the seed ticks are unable to get a 
foothold in order to crawl up on the cattle. A¥here a large number 
of animals are to be treated, but not sufficient to make it advisable to 
construct a dipping vat, spraying the infested animals has given very 
favorable results. The animals should be placed in a chute or a stall, 
or tied to a tree, and then sprayed with Beaumont oil or a 5 per cent 
solution of any of the standard coal-tar dips. The solution may be 



TEXAS FEVER AND ITS PREVENTION. 81 

applied by means of a force pump, such as is used by orchardists to 
sprav fruit trees, or by placing the solution in a barrel upon a Avagon 
or on a platform above the animals and allowing the fluid to gravi- 
tate through a hose, to the end of whicli is attached an ordinary 
sprinkling nozzle. The solution is then allowed to flow over the skin 
of the animal, especially upon the legs and under portions of the 
body. If the cattle are on tick-infested pastures, tliis treatment — 
either smearing or spraying — must be continued tlirough the whole 
season, and if thoroughly done it will leave the fields free from ticks 
the following 3^ear. 

Dipping in a vat. — Man}^ efforts have been made to discover a 
practical method for dipping cattle to destroy ticks Avithout injury to 
the cattle, and the Bureau has experirnented for years with this object 
in view. Xumerous kinds of dips have been used and many failures 
have been recorded, but apparently a successful one has been found in 
the crude oil — so-called Beaumont oil — obtained from certain Texas 
wells. This oil has now been used on a rather large scale, and it has 
been very successful in killing ticks without at the same time mate- 
rially affecting the health of the cattle when the proper precautions 
have been observed. In fact, it is distinctly superior to any of the other 
dips that have been tested. In these experiments it was found that a 
light oil heavily charged with sulphur is the most desirable for 
dipping cattle, as the heavy oils injure the animals dipped in them. 
An oil with 40 per cent of its bulk capable of boiling between 200° 
and 300° C, having a specific gravity between 22^° and 24^° Beaume, 
and containing 1^ to 1^ per cent of sulphur is most desirable, and 
these requirements should be stipulated before purchase. In a recent 
dipping of 57,000 head of cattle on the Kansas and Osage Indian 
reservations the results were very highly satisfactory, both as regards 
the eradication of the cattle tick and the after results of.the dipping, 
since the loss from all causes was less than 0.75 per cent. This loss 
represented in dollars and cents would amount to a very small portion 
(about one-twelfth) of the loss incurred by the sale of these animals 
as " ticky " cattle in the stock yards of the Xorth. Other cattle 
dipped in the same oil, but under conditions that can not be con- . 
sidered parallel, suffered more severely. In order to obtain the best 
results, the animals, after dipping, should not be unduly exposed to 
the hot sun nor driven any considerable distance, but should receive 
plenty of food and good water. They should be allowed to stand 
for four or more days after dipping and prior to shipment. Dip- 
ping should not be attempted until after they shall have shed their 
winter coats, as a large percentage of all cattle dipped before the 
heavy coat is lost suffer from a severe irritation of the skin. The 
method usually adopted in dipping cattle is to construct a narrow^ 
swimming tank with a chute at one end for the entrance of the 



32 BUREAU OF ANIMAL INDUSTRY. 

cattle and a sloping exit at the other end where the cattle emerge 
after getting a uniform coating of oil in passing through the vat. A 
drip chute, or floor, is connected with the exit Avhere the excess of oil 
is allowed to drip off the animals and to drain into the vat. Plans 
and sj^ecifications for installing a dipping plant suitable for either 
small farms or large ranges are published in Farmers' Bulletin No. 
152, which may be obtained from this Department. It is relatively 
more expensive to dip cattle in the South, where the farms and plan- 
tations contain a small number of cattle, than in the range country of 
the Southwest, where this method of eradicating ticks becomes not 
only plausible and practicable, but also economical. AYhen cattle 
have been properly dipped in Beaumont crude petroleum or any other 
approved petroleum under the supervision of a veterinary inspector 
and by him found free of infection, they may be shipped to any point 
above the quarantine line, subject only to such restrictions as may be 
imposed at the point of destination. Such cattle must be shipped in 
clean, disinfected cars, and must not be driven through the quarantined 
area or be unloaded therein, except at those points designated by the 
Secretary of Agriculture. It is earnestly recommended that such 
shipments shall not occur earlier than four to eight days after the 
dipping is performed. 

By the " soiling " method. — This method of freeing cattle of ticks 
was suggested by Curtice. It is based upon a knowledge of the life 
history of these parasites. The time required for the female tick to 
lay eggs and the latter to hatch — in other words, the time spent on 
the ground — is rarely less than three weeks, and the period required 
by the seed ticks to molt and mature — or the time spent on the cattle — • 
is usually from twenty to forty-five da^^s. When cattle infested with 
ticks are to be cleaned for any reason — as, for instance, before being 
placed on npninfested pastures — it is recommended that the cattle 
be kept in a small tick- free inclosure for three weeks, when many 
of the ticks will have fallen off. They should then be removed and 
placed in a similar paddock for another three Aveeks. At this time 
the cattle should be examined, and if found free from ticks they may 
be placed in the noninfested pasture at once. On the other hand if 
any ticks are observed the cattle should be placed in a third pen for 
tAvo weeks more. By this time even the youngest ticks that were on 
the cattle at the start will have matured and dropped^off; and as 
the animals are removed from each pen before they could possibly 
become reinfested with the seed ticks that hatch from the eggs of 
the females that fell off, they are now tick free. The same pens can 
not be used repeatedly for this purpose Avithout thorough disinfection, 
as they become infested Avith young ticks, Avliich w^ill at once attack 
cattle if giA^en an opportunity to do so. Care should be taken that 
hay fed the animals in these pens is from noninfested fields. 



TEXAS FEVER AND ITS PREVENTION. 38 

HOW TO FREE PASTURES OF TICKS. 

How to rid pastures of ticks without destroying the vegetation on 
them was for a long time a problem. While this nvAx be impossible 
on large ranches, it has been successfully accomplished on small 
farms by systematic elforts based upon a knowledge of the life his- 
lor}^ and the habits of the cattle ticks. The most satisfactory as well 
as the most practicable methods have been found to be as follows : 

By excluding cattle for a definite period. — The removal of animals 
from an infested pasture for a stated period will cause all ticks 
present therein to starve and the pasture will thus become tick-free. 
One method of accomplishing this result is to divide the pasture into 
two parts by a double line of fence. This fence should be board- 
tight at the bottom to prevent ticks from crawling out, and there 
should be a 10-foot space between the two lines so that the ticks 
would be unable to crawl across to the opposite pasture if the}^ should 
perchance get out. One of these pastures is then kept free from 
cattle, horses, mules, and asses from spring to late fall, or, better, 
until January. By this time it will be free of ticks and ready for 
tick-free cattle that have been cleaned by any of the methods above 
described; then the other pasture is abandoned for the same period 
of time. 

Butler states that the pasture may be kept free of ticky animals for 
a shorter period with equally beneficial results, and recommends the 
following method : 

The tick-infested cattle should be removed from their pasture on 
September 1, cleaned of ticks b}^ any of the methods previously men- 
tioned, and placed in a cultivated field or pasture where no ticky ani- 
mals have been for at least six months and where they can not come 
in contact with ticky animals or ticky soil. The original pasture 
should not be restocked until the following spring (April), at which 
time all the eggs laid there before September 1 will have hatched, 
the seed ticks will have starved, and the pasture will be free of ticks. 
It may then be used for cattle that have no ticks upon them. In 
case the cattle are not free of ticks when placed in the cultivated field 
or noninfested pasture on September 1, they will infect this field and 
will carry ticks to the original pasture if placed there in the spring. 

By cultivation. — Another method of destroying ticks on pastures 
is to cultivate the soil for a year without permitting any ticky cattle, 
horses, or mules on the ground during this period. After this treat- 
ment the field will be without any Texas-fever ticks and may be re- 
stocked with cattle not infested with these parasites. 

By burning off the grass. — Pastures that are too large to be dis- 
infected by the above measures or those grazing lands that are open 



34 



BUREAU OF ANIMAL INDUSTRY. 






I 



^if^^ 





KG 









CN4 












TEXAS FEVEK AND ITS PREVENTION. ' 35 

and can not be inclosed, or ranches where a division of tlie pasture is 
impracticable, ma}' be freed from ticks by burning them otf in the 
spring or fall and then keeping tick-infested animals from the land. 
It is advisable to burn off the grass in the spring when practicable, 
as this permits the pasture to recover quickly and to supply feed in 
several weeks. 

now TO FREE CATTLE AND PASTT^RES OF TICKS AT THE SA^rE TTNfE. 

By the '' feed-lot " metliod. — The " feed-lot " method has been re- 
cently recommended by Morgan after conducting field experiments 
in Louisiana, and has for its object the ridding at the same time of 
pastures and cattle of -the fever tick. This plan, like the "soiling" 
method, suggested by Curtice, is based upon the length of time the 
tick lives upon cattle and the period required for the eggs to be laid 
and hatched and the seed ticks, to attach themselves to their host. 
For carrying out this idea take a field which has been sown to corn, 
millet, sorghum, or other forage and fence off three lots within such 
a field, in one of which the ticky cattle are placed on June 1 by 
removal from their customary pasture." (See fig. 2.) In the first 
feed lot the greater number of ticks drop off and lay eggs. After an 
interval of tAventy days and before these eggs have had time to 
hatch, the cattle are moved to the second inclosure, where they are 
kept another twenty days, when they will in -many instances be free 
of ticks and can be turned into the forage field. However, in case 
ticks are still present, the cattle should be placed in a third paddock 
for fifteen days longer. All the ticks that were on the animals when 
placed in the feed lots will have dropped off now, and, as the cattle 
leave each feed lot before they can become reinf ested by the seed ticks 
which hatch from the eggs of the ticks that fall off, they will be clean 
and safe. These tick-free cattle are then pastured in the sorghum, 
corn, or millet field containing the feed lots and the latter are plowed 
immediately after the cattle are taken out, their edges are sprayed 
with Beaumont oil, petroleum, or other disinfectant substances, and 
the soil is cultivated. The cattle are kept in the forage field until 
Xovember 15, or even later, when all the ticks on the regular pasture 
will have died of starvation from the exclusion of cattle since June 1, 
and the tick-free animals can then be replaced on this tick-free pas- 
ture. In adopting this method it is essential that the feed lots be 
inclosed by a fence which is board-tight along the ground, and that 
this fence be watched carefully and disinfected occasionally to pre- 
vent the ticks from getting into the forage field; a single furrow 
could be thrown up on both sides of the fence for the same purpose. 

a From our experience the two lots recommended by Morgan would not be 
sufficient under all conditions. 



36 "^ ■ BUREAU OF ANIMAL INDUSTRY. 

These feed lots should be situated along the edge of the field m order 
that the cattle in changing from one lot to the other may pass, as 
directh^ as possible, through a portion of an adjoining cultivated or 
tick-free field, so that if the ticks fall off during this drive they will 
not infest the forage field, and later the cattle when pastured 
therein. The cattle should be fed on the annual crops while in these 
lots, but never upon crops obtained from infested pastures, as such 
food may contain seed ticks. Water may be supplied by piping 
from a well, spring, or creek, by carting it to the feed lots in barrels, 
or b}^ placing the fence so as to include a spring or portion of a 
creek, provided the latter does not flow through an infected pasture 
a short distance above. 

By imstiiTe rotation. — A very satisfactory method for freeing cattle 
as well as pastures of the cattle tick is by pasture rotation, which com- 
bines the suggestions of Curtice, Butler, and Morgan. It is based 
upon the knowledge that b}^ severing the relation of the fever ticks 
and the animals upon which they develop these ticks will perish. To 
adopt this plan first divide the infected pasture into two parts, which 
is best accomplished by a double line of fence with a 10-foot space be- 
tween the lines to prevent ticks crossing from one pasture to another 
(fig. 3). In order to observe all possible precautions, this fence 
should have either a furrow thrown up against it or a board or 
rail placed tightly along the bottom to help keep the ticks within. 
All animals that carry the cattle tick are excluded from the first half 
of the jDasture, which may be termed pasture No. 1, from June 1 
until November 10, at which time all the ticks that were there will 
have perished from want of a host and the field will be ready for re- 
ceiving tick-free cattle. The ticky cattle, on being removed from 
pasture No. 1 on June 1, are placed in the other half of the original 
pasture, which may be called pasture No. 2, where they are kept from 
June 1 to September 10. They may now be partly cleaned of ticks 
by placing them at the latter date (September 10) in a cultivated 
field — for instance, a rye or vetch or wheat and vetch field — and by 
keeping them therein for twenty days, when a large number of ticks 
will have fallen off. The partly cleaned cattle may then be removed 
on September 30 to a field sown to corn and sorghum, corn and cow- 
peas, or a combination of corn, sorghum, and cowpeas, or other 
forage crojDS. 

In this field most of the remaining ticks, if not all of them, will 
have dropped from the animals within twenty days, but in a few in- 
stances the cattle may still be infested, so the animals should be moved 
on October 20 to a cotton field in which rape or crimson clover had 
been sown at the last cultivation for the purpose of furnishing food 
for the cattle while there. The crops should have been gathered from 



J 



TEXAS FEVER AND ITS PREVENTION. 



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38 BUREAU OF ANIMAL INDUSTRY. 

all these fields before turning in the cattle. Here they are kept for 
another twenty days (to November 10), not because they would not 
be free of ticks at an earlier date, but on account of the desire to 
keep cattle away from pasture No. 1 until November 10. On this 
date these clean cattle are returned to pasture No. 1, which 
will now be tick-free as a result . of the exclusion of animals 
since June 1. These cattle should be kept in this pasture until 
May, hj which time the ticks in pasture No. 2 will have 
starved, owing to the absence of animals therefrom since Sep- 
tember 10. Both the cattle and pastures will now be tick-free and 
the double line of fence between the two fields can be removed 
and the original pasture restored. This plan, as rej^resented by the 
diagram, is merely a suggestion of arrangement and may easily be 
varied with regard to the selection of crops and the location of pas- 
tures to suit the demands of individual farms. To prevent ticks 
from crawling under either of the fences between fields III and IV 
and fields IV and V, it is necessary to have a board or rail placed 
tightly on the ground along these lines of fence, or to throw up 
a single furrow along both sides of the fences. To avoid the danger 
of infestation from the outside, care should be taken to feed the 
animals, in those cases where the pastures or fields are overstocked, 
on hay cut from tick-free fields, and to keep out Avork oxen, mules, 
and horses that may harbor fever ticks, thus preventing reinfesta- 
tion of the pasture. When the cultivated fields are on a slope it 
is advisable to use the loAvest field first, in order that the ticks 
droj)ped Avithin may not be Avashed by drainage upon the adjoin- 
ing fields Avhich are later to hold the cattle. For the same reason, 
Avhere a stream runs through the fields upon Avhich the cattle are to 
be placed, the field farthest removed from the head Avater should 
be used first. ^^Hiere an endeavor is made to rid a farm of ticks, 
it is essential that the Avork animals (oxen, mUles, and horses) used 
in cultivating the fields be curried to keep off the ticks and prevent 
the latter from being carried into these fields. Cats should also be 
kept from the pastures and fields; for, although they do not harbor 
the mature ticks, seed ticks have been found on them, and, AAdiile 
these seed ticks remain only for a short period, this time may be 
sufficient to allow them to be carried into the disinfected pastures, 
Avhere they may fall off and reinfest the soil. If a farm or planta- 
tion consists of a pasture and but one field under cultiA^ation, the 
aboA^e plan can be made applicable by fencing off three inclosures in 
the latter and by rotating the cattle in them every twenty days in 
the manner just described. The same precautions should be observed 
in changing the cattle from one lot to another and in preA'enting ticks 
from getting into the cultivated field, as are mentioned above. 



TEXAS FEVEK AND ITS PREVENTION. 39 

IMMUNIZATION Ol' SUSCEPTIBLE CATT1>E. 

By hlood inoculation. — It is often desirable to ship Avell-bred cat- 
tle into infested districts, that they may be used to improve the 
quality of the native cattle already there. Previous to the discov- 
ery of the cause of Texas fever, it was found to be wellnigh impos- 
sible to introduce purebred cattle from the North into any of the 
infected regions Avithout suffering great loss — sometimes as high 
as 90 per cent — within a few months of their arrival at their South- 
ern destination. At first it was thought that the fatalities Avere due 
to climatic clranges, but later the discovery was made that Texas 
fever was causing these numerous deaths. 

It has now been found practicable to immunize this class of cattle 
so perfectly that the losses which follow their transportation to a 
tick-infested region are reduced to a minimum. Young animals six 
to jfifteen months old should, so far as possible, be selected for this 
purpose, as they are more readily immunized than adults, are more 
easily handled, and the dangers which may arise from pregnancy 
while undergoing the immunizing treatment are thus avoided. 

Immunity in these cattle is obtained by introducing the micro- 
parasite of the blood into their systems. It may be done by direct 
artificial inoculation or by placing virulent young ticks upon the 
animals and allowing them to perform the inoculation in the natural 
manner. The subcutaneous injection of a small amount of defibri- 
nated virulent blood has been found, by means of prolongecl experi- 
ment, the preferable method, as the number of microorganisms intro- 
duced can be more accurately gauged from the syringe than by 
alloAving the infection to be produced by bites of ticks. Two or 
three inoculations, if repeated at proper intervals, are accomplished 
with greater safety to the animal than Avould be possible by means 
of a single inoculation. The amount first injected shoidd be small 
and then gradually increased in the succeeding treatments. 

The inoculation always results in a more or less serious attack of 
Texas fever. Besides having a fever, there is great diminution of 
red blood corpuscles, and in about 3 per cent of the cases a fatal termi- 
nation ; but the proportion of deaths resulting from the inoculation is 
small when compared Avith the fatalities among untreated animals 
taken into infested districts. To this number should be added those 
animals (less than T per cent) that do not receive sufficient immunity 
b}^ this method and Avhich succumb when exposed to infested pastures. 
Combining these failures it Avill be seen that by this method of im- 
munization, instead of a loss of 90 per cent among breeding stock 
taken South more than 90 per cent can be saA^ed. The animals should 
be carefully nursed through the attack and their symptoms treated 
as indicated on page 29. 



40 BUREAU OF ANIMAL INDUSTRY. 

Immunizing inoculations are now being made by the veterinarians 
of most of the agricultural experiment stations of the Southern States 
without cost for the services rendered, a charge being made merely 
for the actual value of food consumed and attendants' Avages. These 
veterinarians have also issued station bulletins which describe fully 
the necessary steps to be taken in securing the blood and injecting it 
into the animals to be immunized, so that the stock owner can follow 
the instructions with prospects of getting good results. 

This operation is not a difficult one, and excellent results will follow 
where absolute cleanliness and ordinary care have been used, but 
undoubtedly the best results will be obtained by those who have 
thoroughly familiarized themselves with the nature of the disease 
and are experienced in extracting blood from animals. Two methods 
are in use and will be described separately. One consists in drawing 
the blood from the jugular vein of an immune animal and immedi- 
ately injecting it into the cattle to be immunized. It is compara- 
tively simple, requires few instruments, and can be satisfactorily 
carried out where a small number of animals are to be immunized 
and if a suitable immune animal is close at hand. First, select an 
immune animal which is in good health and which is infested with 
fever ticks or had them the preceding year. Fasten the animal 
securely, either by tying, throwing, or by placing in a chute. Clip 
the hair from a space about 4 inches in diameter over the jugular vein 
on the upper third of the neck, wash the skin thoroughly with a 5 per 
cent solution of carbolic acid, and then fasten a strap or rope around 
the neck below the hairless area and draw it tight in order that the 
blood in the vein will be stopped, causing distention. With a large 
hypodermic syringe needle previously sterilized in a 5 per cent car- 
bolic-acid solution, puncture the vein at a slight angle, directing the 
point forward. When the needle enters the vein the point can be 
rotated freel}^ in contrast to the restricted movements if still in the 
tissues, and the blood will either drop or flow from the opening in the 
needle. Attach the disinfected syringe to the needle with piston in 
and gradually draw out the piston until the chamber of the syringe 
is full of blood when the needle is withdrawn. The blood, before it 
has had time to clot, is immediately injected into the animals to be 
immunized and which have been previously tied or restrained, the 
hair clipped, and the skin disinfected at the seat of injection in the 
region of the shoulder. Inject then from 1 to 3 cubic centimeters, 
according to the age of the animal, under the skin of each animal 
until the blood is exhausted. When more animals are to be inoculated 
than one syringeful will inject, the operation may be repeated in the 
same manner. The only objection to this method is the possibility of 
the blood clotting in the syringe, but with practice and promptness 
this can be easily overcome. 



TEXAS FEVER AND TTS PREVENTION. 41 

The second method is better suited for tlie iiiocidation of a hirii^e 
number of cattk' or where the iuunune animal is at ;i distance from 
the cattle to be innnunized. 

The preliminary steps — the clipping of the hair, disinfection of 
the skin, placing the rope around the neck to distend the jugular 
vein, and restraining the animal — are the same as for the first method. 
In })uncturing the vein it is advisable to use a small trocar and canula 
after sterilization in a 5 per cent carbolic-acid solution, and, when 
the vein has been entered, to draw out the trocar, allowing the blood 
to flow through the canula into a perfectly clean and sterile vessel. 
After sufficient blood has been drawn for the animals to be injected, 
a clean stick, previously sterilized by boiling in water, is placed in 
the vessel containing the blood and the latter is stirred for ten min- 
utes or so or until the fibrin in the blood is Avhipped out. The remain- 
ing blood, known as defibrinated blood, is then inoculated under the 
disinfected skin of the animals to be immunized, as in the first 
method. This blood should be used as early as possible after draw- 
ing, to prevent it from becoming contaminated and decomposed. 
The jDlace where this injection is made is immaterial, but for conven- 
ience a point just behind the shoulder is usually chosen. The dose 
and number of injections vary with the individual animals. As a 
rule, it may be stated that 1 cubic centimeter should be injected into 
an old animal coming into the infested district, 2 cubic centimeters 
for a 2-year-old, and 3 centimeters for an animal 9 to 15 months old. 
It will be observed that, unlike the usual custom of applying treat- 
ment, the older animals take less than the young ones, owning to their 
greater susceptibility to the disease. Where an animal has reacted 
well to a first injection and shows a very high temperature, great 
I'eduction of red blood cells, or other symptoms indicative of reac- 
tion, it will not be necessary to repeat the injection, but in those 
cases Avhere the reaction is slight, a second injection should follow 
after an interval of forty days, and, if need be, a third injection after 
a similar lapse of time, always increasing the size of dose 50 per cent. 
A thermometer, to indicate the course and severity of the disease, 
is indispensable in this work. Usually, after three to ten days, some- 
times longer, the inoculated animals show^ a mild type of Texas fever, 
which runs a course of from six to eight days and is followed in about 
thirty days after the injection with a second attack of a milder 
character than the first. After forty days, when the animal has 
entirely recovered from the inoculation, a second injection may be 
given to increase its immunity. In some cases a very severe type of 
fever folloAvs the first inoculation, requiring careful nursing and 
treatment, as suggested aboA^e. A second, milder attack follow^s 
usually in about thirty to forty days, after which the animal need 
have no further inoculations. It is advisable to prevent any ticks 



42 BUREAU OF ANIMAL INDUSTRY. 

from getting' on the cattle until sixty days after their inoculation or 
until they have fully recoA'erecl, at which time a few ticks ma}^ be 
placed upon them in order to reenforce their innnunity. Naturally 
this time varies according to the type of the attack. As the best 
results Avith these immunizing experiments have been obtained in 
cool Aveather and Avith young cattle, it is recommended that animals 
from 6 to 15 months old be selected for inoculation, and that they 
be immunized during the late fall or Avinter months, in order that 
they may enter tick-infested pastures in the spring Avithout danger. 
^By infesting with ticks. — Immunity may also be induced in sus- 
ceptible animals by placing a limited number of fever ticks upon 
their bodies in order to produce the disease naturally. For this pur- 
pose only animals less than 1 year of age should be used, as the 
method is not applicable for older and more susceptible animals. 
Upon the bodies of these young cattle from tAventy-fiA^e to fifty seed 
ticks should be placed, Avhich in the course of about ten days Avill 
occasion a rise of temperature and a mild form of Texas fever. TVlien 
the animal has entirely recovered from this attack, a second crop — 
double the number first used — should be applied to the animal in 
order to increase its poA^^er of resistance Avhen pastured on infested 
soil. In order to. carry out this method successfully, a constant sup- 
ply of seed ticks must be at hand. This can be accomplished by plac- 
ing the mature females in a Mason fruit jar among some dirt and 
leaves and keeping them in a Avarm place. In a feAA^ Aveeks the eggs 
Avill haA^e been laid and hatched, and a number of seed ticks will be 
present for use in infesting the cattle to be immunized. By placing 
a feAv adult females in the jar CA^ery tAvo months there will always be 
a supply of these young ticks. This method of producing immunity 
by controlled tick infestation is not so safe as blood inoculation, since 
the quantity of germs injected can be more accurately regulated by 
means of a syringe. 

FEDERAL SANITARY REGULATIONS. 

The sanitary regulations Avhich have been enacted by the Depart- 
ment of Agriculture for the control of cattle shipments from the in- 
fected districts haA^e for their initial purpose the preA^ention of the 
transportation of cattle ticks from infected regions to those that 
are not infected, either upon cattle or in stock cars or other conveyer, 
during the season of the year Avhen infection is possible. They are 
based upon the fact that Texas fever is carried north only by the 
cattle tick; and the exclusion of this parasite from the noninfected 
territory has in every instance been :^ound a certain method of ex- 
cluding Texas fever. The regulations governing the movement of 
cattle from below the quarantine line are made yearly by the Secre- 
tary of Agriculture and they define the boundary of infected dis- 



TEXAS FEVER AND TTS PKEVENTTON. 48 

tric'ts. The lino as now dctcM-niincMl starts in Viro-inia on the Atlantic 
coast and passes in a westerly diivction throni>ii ^^il•<>•illia, Noi-th 
Carolina, (irc()r<iia, Tennessee, and a small portion of Kentucky, 
alon<»* the northern border of Arkansas and Indian Territory, thence 
through Oklahoma and Texas to the Ivio (irande and the Mexican 
border, Avhence it passes along the southern boundary of Xcav Mexico 
and Arizona and across the central portion of California to the 
Pacific slope (fig*. 1). This year (1905) cattle may be moved from 
the (juarantined district for purposes other than immediate slaughter 
during November, December, and January into the noninfected 
area within the States of Virginia, North Carolina, Georgia, Ten- 
nessee, Texas, Oklahoma, and California, and to the States of Mis- 
souri and Kansas and the Territories of Arizona and. New Mexico, as 
may be provided for in the regulations of these States and Terri- 
tories, and after inspection by and upon written permission of an 
inspector of the Bureau of Animal Industry or a duly authorized 
inspector of the State or Territory to which the cattle are destined, 
and after permission shall have been obtained from the proper officer 
of the said State or Territory. All cattle from the quarantined district 
destined to points outside of the States and Territories above named 
may be shipped without inspection between November 1 and January 
81, inclusive (the open season), without restrictions other than may 
be enforced b}^ local regulations at the point of destination. At the 
present time no cattle shall go out of quarantine, except for immediate 
slaughter, during that portion of the j^ear included betw^een the dates 
of February 1 and October 31, and known as the closed season. 
These cattle must be slaughtered within Iavo weeks after arrival at 
their destination, and the regulations of the Secretary of Agriculture 
concerning their handling and movement shall be enforced. The 
following is an abstract of the regulations in force May 1, 1905 : 

Cattle coming from the infected districts during the closed season 
can not be driven, but must be conveyed in cars or boats placarded as 
containing " Southern cattle," and bills of lading, w-aybills, and con- 
ductors' manifests shall have this information written upon them. 
When the cattle are unloaded for feeding, w^atering, or other pur- 
pose they must be placed in pens reserved for such animals only, in 
which native stock is not allow^ed, and a large sign with the words 
"• Quarantine pens " or " Quarantine yards " must be conspicuously 
placed on all such inclosures. On unloading at their destination, 
only the chutes, alleyways, and pens reserved for Southern cattle 
shall be used. Before the cars or boats which carried these animals 
are again used their entire interior must be thoroughly washed wdth 
water, after the removal of all litter and manure, and then disinfected 
with a mixture made of 1-J pounds of lime and J pound of 100 per 
cent carbolic acid to each gallon of water, or with a solution made 



44 BUREAU OF ANIMAL INDUSTRY. 

by dissolving 4 ounces of chloride of lime to each gallon of Avater. 
The litter and manure may be disinfected as above, or, if not disin- 
fected, it shall be stored away where cattle can net reach it during 
the period from February 1 to October 31 of each year. All chutes, 
alleyways, and pens used en route and at destination but not reserved 
for the exclusive use of Southern cattle shall be similarly disinfected. 
Where these animals are yarded adjacent to cattle from above the 
line, at least a 10-foot space not occupied by cattle must be left be- 
tween, on each side of which shall be a tight board fence not less 
than 5 feet high. 

In consequence of the enforcement of these quarantine regulations 
Texas fever has been practically prevented in the noninfected dis- 
tricts during the last several years, and little or no hardship has been 
caused to those stockmen handling cattle from the infected areas. 
Previous to their adoption the tick-infested district was rapidly ex- 
tending northw^ard, but since the quarantine line was established and 
rational regulations enforced it has gradually been moved farther 
south. This problem of still further reducing the infected area is of 
the greatest importance to the cattlemen of the South — in fact, to 
those on both sides of the line — and one which is receiving special 
consideration by this Department as well as by many of the inter- 
ested States. 

OTHER IMPORTANT MEASURES FOR REDUCING THE INFECTED AREA. 

The first and probably the most important step in eradicating the 
cattle tick is to start and continue a plan of educating the cattle owner 
as to the nature of Texas fever and the method of its transmission. 
This may be best accomplished through farmers' institutes, the 
issuance of press bulletins and circluars, the publication of short 
articles in agricultural journals, and, best of all, by personal inter- 
course between the agricultural population and educated stock in- 
spectors who are capable of imparting the necessary information. 
There can be no doubt that the crying need of the infected country is 
not so much the development of new ideas for exterminating the 
cattle tick as it is to remove all doubts of stockmen regarding what 
they term the " tick theory," and to impress upon them the funda- 
mental truths concerning the cattle tick, its relation to Texas fever, 
and simple methods for its extermination. In other words, the stock- 
man himself must be made to realize the proved facts regarding this 
disease, and then to appreciate the feasibility of eradicating the ticks 
which cause it. There is still a large number of cattlemen who are 
incredulous regarding the nature of Texas fever and until the abso- 
lutely established facts of the disease are known and accepted it w^ill 
be impossible to have intelligent cooperation and earnest endeavor 



TEXAS FEVER AND ITS PREVENTION. 45 

ainona* those most vitallv interested to onulicate the Texas-fever tick 
and prevent the disease. In some counties within the infected dis- 
trict bordering- on the quarantine line the local authorities have 
organized cattle clubs composed of stockmen with the view of inter- 
esting them in exterminating the ticks from their premises, and in 
preventing cattle in adjoining tick-infested sections from coming 
upon their property. These organizations are the means of dissemi- 
nating general information respecting Texas-fever infection and the 
cause of the restrictions placed on the cattle in the infected district, 
and through them a concerted action of the cattle owners is obtained, 
resulting in the control and final eradication of the infection Avithin 
a portion or the whole of a county. When a county has been handled 
in this manner a thorough inspection is made at the proper time by a 
representative of the Bureau of Animal Industry, and if the condi- 
tions warrant such action it is released from quarantine. The success 
of such clubs in accomplishing both these purposes is a constant re- 
nnnder of what other organized stockmen could do. The desirability 
of rational legislation based on an accurate knowledge and a complete 
understanding of the disease is self-evident. Every county in all the 
infected States should have stock or '' no fence " laws to prevent 
stock owners from allowing ticky cattle on commons, nninclosed 
lands, or highways. Especially should these be enforced in the States 
on the quarantine line and in those having many noninfected areas in 
the quarantined region. In the former case this would assist in 
securing a position aboA'e the line, and in the latter it would tend to 
enlarge the tick-free sections. In a number of counties in Virginia, 
Xorth Carolina, and Georgia, where the laws prohibit cattle from 
running at large and compel fencing of pastures, the cattle tick soon 
disappeared, and such tick-free counties were placed above the quar- 
antine line without am^ loss having followed from the cattle in these 
districts. Butler suggests that each county should have laws pro- 
viding for a farm-to-farm inspection, with employment of a stock 
inspector, in order to locate the tick-infested farms. Stockmen 
themselves should organize in order to aid the county in its endeavor 
to exterminate the ticks: and information concerning their habits, 
the importance of their extermination, and methods for accomplish- 
ing it should be furnished to owners of infected lands. With the 
active cooperation of the people and the enforcement of the stock 
laws, much territory may be freed of ticks at a very moderate annual 
expense. If ticks on one farm, one section, one county, can be ex- 
terminated, it certainly should be possible for the entire State or 
entire infested district to be cleaned. 

In all the infected States a uniform legislation should be secured on 
the subject of communicable diseases, particularly Texas fever, by 



4(5 BUREAU OF ANIMAL INDUSTRY. 

which these States avouIcI be enabled not only to cooperate with the 
Federal Government, but also with each other. Such laws should 
prevent the entrance of ticky cattle into the State, unless for slaughter, 
compel the holding* of cattle on inclosed premises, enforce an effectual 
quarantine on all badly infected areas, make it compulsory to clean 
up the infection Avhere the ticks are few in number, and stipulate 
that the stock inspectors appointed for this work must be educated 
and experienced in the subject of Texas fever. Then, after securing 
these laws in the various States, they should be enforced, all violat- 
ers should be punished, and such punishments should be given wide- 
spread iDublicity. Such action is absolutely necessary before any 
decided progress can be made in the general extermination of the 
fever ticks and in the reduction of the infected areas. 

For some years past the Bureau of Animal Industry has had a 
number of inspectors stationed along the quarantine line who have 
been required to disseminate information relative to the nature of 
Texas fever, to investigate reported violations of the quarantine 
regulations, to inspect cattle in those counties Avishing to be placed 
above the line, to keep a careful Avatch over the uninfected pens at the 
railroad feeding stations in the infected district Avhere tick-free cattle 
are rested, fed, and Avatered in passing through, and to examine for 
the presence of ticks all cattle that come out of the modified quaran- 
tined counties. These modified districts are those Avherein the infec- 
tion is confined to small areas and Avhich are placed provisionally 
above the line subject to inspection of all cattle leaving that area for 
noninfected territory. 'No cattle are permitted to come into the dis- 
trict unless they come from above the quarantine line. In certain 
cases where a county ha& only a feAA^ infected farms, the Department 
has at times accepted the declaration made by the State officials to 
enforce an adequate quarantine on these premises and has alloAA^ed the 
entire count}^ to be placed aboA^e the line. Such concessions as these 
indicate the interest taken in relieving the burden of quarantine, and 
Avhile some unfortunate results have folloAved, the beneficial effects 
have far exceeded them. 

The authority of the Federal veterinary inspectors is limited within 
the boundary of the States, and the progress they are able to make 
under these conditions is slow. In order to giA^e these men greater 
influence within the State, it might be advisable to have* the State law 
permit of their appointment as officers of the commonwealth to serve 
without compensation. Thus, in the eradication of foot-and-mouth 
disease from New England and of scabies from the West, some States, 
such as Massachusetts, Wyoming, and others, made State officers of 
the GoA^ernment men, which resulted in a larger amount of work 
being performed and Avith greater expedition. The restrictions 
which are necessarily thrown around a Federal insjDector Avhen deal- 



TEXAS FEVER AND ITS PREVENTION. 47 

iiig with a local (luestion of interstate iinj)()rtaiu'e would by these 
means be relieved. 

It would be advisable for the State or Federal (lovernnient, or 
both, to make sufficient yearly appropriations for the j^urpose of giv- 
ing object lessons by means of demonstration farms, where approved 
methods for eradicating Texas-fever ticks could be carried out. Re- 
sults of such practicable demonstrations would have a very whole- 
some effect upon other owners of stock in that section and Avould 
encourage the application of similar methods for a like purpose. 
It is generally admitted that extermination of ticks along the quar- 
antine line is desirable, but the disinfection of pastures Avithin the 
line is thought by some to be inadvisable. In fact, these writers 
recommend placing a f-eAv ticks on the cattle while young to render 
them immune when in these tick-free pastures. This plan of infect- 
ing clean pastures is a questionable proceeding, and if carried out 
by all below the line would result in producing thousands of ticks 
where now there are hundreds only. It must be remembered in this 
connection that the cow tick is not only the carrier of Texas fever, but 
is a parasite which deprives its host of much blood, retards grow^th, 
reduces the milking capacity, and induces an irritable state known 
as " tick worry." Even if Ave exclude its fever-carrying property, 
it should still be exterminated in all districts, Avhether on the quar- 
antine line or beloAv it, for the same reasons as lice and other A^ermin 
are destroyed. Furthermore, cattle may noAv be rendered immune 
by blood inoculations, and the necessity for having ticks on the ani- 
mals for this purpose does not exist. It Avould therefore seem pref- 
erable to keep noninfected farms free from ticks, and, if they are 
in danger of exposure to these parasites, make the animals immune 
by blood injections. If these injections are made merely Avith the 
AdeAV of preA^enting fatalities among the uninfested cattle Avhen 
exposed to neAvly purchased ticky animals, it Avould be far better to 
remoA^e the ticks from the latter before alloAving them to conmiingie. 
Others buying these susceptible cattle for their oAvn infected pas- 
tures Avould also run the risk of their death from Texas feA^er unless 
previously immunized Avith blood or gradually infested with ticks. 
Notwithstanding the precautions Avhich must be taken to avoid 
losses as a result of noninfected areas in the quarantined zone, it is 
held that, unless these pastures continue free of ticks and other pas- 
tures are added to them, there can be no solution of the Texas- fever 
problem. 

It might be asked, What advantage is it to the stockman beloAv the 
line to clean his cattle and pastures of ticks unless his animals are 
recognized as tick-free and permitted to come North Avithout restric- 
tion? The greatly improA^ed condition and better dcA^elopment in 
all respects of such cattle are sufficient answers to this query, and their 



A. 



48 BUREAU OF ANIMAL INDUSTRY. 



appearance furnishes a marked ('ontrast to that of those which harbor 
these parasites. Furthermore, provision has been made for nonin- 
fected animals to come above the line at any season of the year, but, 
like the ticky cattle, they are subject to the restriction that they be 
dipped in Beaumont crude petroleum ol' other crude oil to prevent 
them from becoming infested in passing through the quarantined dis- 
trict. And they must also be shipped in clean, disinfected cars, and 
must not be driven through the infected area or unloaded therein ex- 
cept at points designated by this Department. 

By the general application of the previously described measures for 
reducing the infected area, supported by well-directed legislation in 
all the infected districts, it would become merely a matter of a short 
period of time before the fever tick would be exterminated and South- 
ern cattle permitted to reach the more favorable markets of the North 
at any time of the year without restraint. Prices would then be 
higher, the demand greater, and the odium attached to ticky cattle at 
the stock yards removed. Purebred Northern cattle could then be 
brought into the South to improve the native breed without danger of 
death from Texas fever. Southern animals could enter the show rings 
of the North without restriction, and the total cost of tick extermina- 
tion would be far less than the amount saved in the first year after it 
had been accomplished. However, much cooperation must be had 
between the farmer and the State and Federal Governments before 
such a desirable result is possible. And in the meantime, with such 
conditions attainable, laxity should not be allowed in enforcing the 
present regulations, National, State, and local, and equal care should 
be taken to enlighten the stock raisers of the infected district as to 
the benefits which will follow their thorough understanding of Texas 
fever and their intelligent assistance in its eradication. 



o 



I 



LEFe'07 



